diff --git a/src/frontends/lean/pp.cpp b/src/frontends/lean/pp.cpp
index 9856ebb3a..d56281763 100644
--- a/src/frontends/lean/pp.cpp
+++ b/src/frontends/lean/pp.cpp
@@ -16,6 +16,7 @@ Author: Leonardo de Moura
 #include "library/private.h"
 #include "library/explicit.h"
 #include "library/num.h"
+#include "library/simple_formatter.h"
 #include "frontends/lean/pp.h"
 #include "frontends/lean/pp_options.h"
 #include "frontends/lean/token_table.h"
diff --git a/src/kernel/formatter.cpp b/src/kernel/formatter.cpp
index 88e524ba7..efaaf93fb 100644
--- a/src/kernel/formatter.cpp
+++ b/src/kernel/formatter.cpp
@@ -6,264 +6,22 @@ Author: Leonardo de Moura
 */
 #include <utility>
 #include "kernel/formatter.h"
-#include "kernel/environment.h"
-#include "kernel/find_fn.h"
-#include "kernel/instantiate.h"
-#include "kernel/free_vars.h"
-#include "kernel/annotation.h"
 
 namespace lean {
-bool is_used_name(expr const & t, name const & n) {
-    return static_cast<bool>(
-        find(t, [&](expr const & e, unsigned) {
-                return (is_constant(e) && const_name(e) == n)  // t has a constant named n
-                    || (is_local(e) && (mlocal_name(e) == n || local_pp_name(e) == n)); // t has a local constant named n
-            }));
+static std::unique_ptr<std::function<void(std::ostream &, expr const & e)>> g_print;
+
+void set_print_fn(std::function<void(std::ostream &, expr const &)> const & fn) {
+    g_print.reset(new std::function<void(std::ostream &, expr const &)>(fn));
 }
 
-name pick_unused_name(expr const & t, name const & s) {
-    name r = s;
-    unsigned i = 1;
-    while (is_used_name(t, r)) {
-        r = name(s).append_after(i);
-        i++;
-    }
-    return r;
-}
-
-bool is_internal_name(name n) {
-    while (!n.is_atomic())
-        n = n.get_prefix();
-    return n.is_numeral();
-}
-
-static name g_x("x");
-pair<expr, expr> binding_body_fresh(expr const & b, bool preserve_type) {
-    lean_assert(is_binding(b));
-    name n = binding_name(b);
-    if (is_internal_name(n))
-        n = g_x;
-    n = pick_unused_name(binding_body(b), n);
-    expr c = mk_local(n, preserve_type ? binding_domain(b) : expr(), binding_info(b));
-    return mk_pair(instantiate(binding_body(b), c), c);
-}
-
-static name g_internal("M");
-name fix_internal_name(name const & a) {
-    if (a.is_atomic()) {
-        if (a.is_numeral())
-            return g_internal;
-        else
-            return a;
-    } else {
-        name p = fix_internal_name(a.get_prefix());
-        if (p == a.get_prefix())
-            return a;
-        else if (a.is_numeral())
-            return name(p, a.get_numeral());
-        else
-            return name(p, a.get_string());
-    }
-}
-
-/**
-   \brief Very basic printer for expressions.
-   It is mainly used when debugging code.
-*/
-struct print_expr_fn {
-    std::ostream & m_out;
-    bool m_type0_as_bool;
-
-    std::ostream & out() { return m_out; }
-
-    bool is_atomic(expr const & a) {
-        return ::lean::is_atomic(a) || is_mlocal(a);
-    }
-
-    void print_child(expr const & a) {
-        if (is_atomic(a)) {
-            print(a);
-        } else {
-            out() << "("; print(a); out() << ")";
-        }
-    }
-
-    bool print_let(expr const & a) {
-        if (!is_let_annotation(a))
-            return false;
-        expr l = get_annotation_arg(a);
-        if (!is_app(l) || !is_lambda(app_fn(l)))
-            return false;
-        name n = binding_name(app_fn(l));
-        expr t = binding_domain(app_fn(l));
-        expr b = binding_body(app_fn(l));
-        expr v = app_arg(l);
-        n      = pick_unused_name(b, n);
-        expr c = mk_local(n, expr());
-        b      = instantiate(b, c);
-        out() << "let " << c;
-        out() << " : ";
-        print(t);
-        out() << " := ";
-        print(v);
-        out() << " in ";
-        print_child(b);
-        return true;
-    }
-
-    void print_macro(expr const & a) {
-        if (!print_let(a)) {
-            macro_def(a).display(out());
-            for (unsigned i = 0; i < macro_num_args(a); i++) {
-                out() << " "; print_child(macro_arg(a, i));
-            }
-        }
-    }
-
-    void print_sort(expr const & a) {
-        if (is_zero(sort_level(a))) {
-            if (m_type0_as_bool)
-                out() << "Prop";
-            else
-                out() << "Type";
-        } else if (m_type0_as_bool && is_one(sort_level(a))) {
-            out() << "Type";
-        } else {
-            out() << "Type.{" << sort_level(a) << "}";
-        }
-    }
-
-    void print_app(expr const & e) {
-        expr const & f = app_fn(e);
-        if (is_app(f))
-            print(f);
-        else
-            print_child(f);
-        out() << " ";
-        print_child(app_arg(e));
-    }
-
-    void print_arrow_body(expr const & a) {
-        if (is_atomic(a) || is_arrow(a))
-            return print(a);
-        else
-            return print_child(a);
-    }
-
-    void print_binding(char const * bname, expr e) {
-        expr_kind k = e.kind();
-        out() << bname;
-        while (e.kind() == k) {
-            out() << " ";
-            auto p = binding_body_fresh(e);
-            expr const & n = p.second;
-            if (binding_info(e).is_implicit())
-                out() << "{";
-            else if (binding_info(e).is_cast())
-                out() << "[";
-            else if (!binding_info(e).is_contextual())
-                out() << "[[";
-            else if (binding_info(e).is_strict_implicit())
-                out() << "{{";
-            else
-                out() << "(";
-            out() << n << " : ";
-            print(binding_domain(e));
-            if (binding_info(e).is_implicit())
-                out() << "}";
-            else if (binding_info(e).is_cast())
-                out() << "]";
-            else if (!binding_info(e).is_contextual())
-                out() << "]]";
-            else if (binding_info(e).is_strict_implicit())
-                out() << "}}";
-            else
-                out() << ")";
-            e = p.first;
-        }
-        out() << ", ";
-        print_child(e);
-    }
-
-    void print_const(expr const & a) {
-        list<level> const & ls = const_levels(a);
-        out() << const_name(a);
-        if (!is_nil(ls)) {
-            out() << ".{";
-            bool first = true;
-            for (auto l : ls) {
-                if (first) first = false; else out() << " ";
-                if (is_max(l) || is_imax(l))
-                    out() << "(" << l << ")";
-                else
-                    out() << l;
-            }
-            out() << "}";
-        }
-    }
-
-    void print(expr const & a) {
-        switch (a.kind()) {
-        case expr_kind::Meta:
-            out() << "?" << fix_internal_name(mlocal_name(a));
-            break;
-        case expr_kind::Local:
-            out() << fix_internal_name(local_pp_name(a));
-            break;
-        case expr_kind::Var:
-            out() << "#" << var_idx(a);
-            break;
-        case expr_kind::Constant:
-            print_const(a);
-            break;
-        case expr_kind::App:
-            print_app(a);
-            break;
-        case expr_kind::Lambda:
-            print_binding("fun", a);
-            break;
-        case expr_kind::Pi:
-            if (!is_arrow(a)) {
-                print_binding("Pi", a);
-            } else {
-                print_child(binding_domain(a));
-                out() << " -> ";
-                print_arrow_body(lower_free_vars(binding_body(a), 1));
-            }
-            break;
-        case expr_kind::Sort:
-            print_sort(a);
-            break;
-        case expr_kind::Macro:
-            print_macro(a);
-            break;
-        }
-    }
-
-    print_expr_fn(std::ostream & out, bool type0_as_bool = true):m_out(out), m_type0_as_bool(type0_as_bool) {}
-
-    void operator()(expr const & e) {
-        scoped_expr_caching set(false);
-        print(e);
-    }
-};
-
 std::ostream & operator<<(std::ostream & out, expr const & e) {
-    print_expr_fn pr(out);
-    pr(e);
+    if (g_print) {
+        (*g_print)(out, e);
+    } else {
+        throw exception("print function is not available, Lean was not initialized correctly");
+    }
     return out;
 }
 
-formatter_factory mk_simple_formatter_factory() {
-    return [](environment const & env, options const & o) { // NOLINT
-        return formatter(o, [=](expr const & e, options const &) {
-                std::ostringstream s;
-                print_expr_fn pr(s, env.prop_proof_irrel());
-                pr(e);
-                return format(s.str());
-            });
-    };
-}
-
 void print(lean::expr const & a) { std::cout << a << std::endl; }
 }
diff --git a/src/kernel/formatter.h b/src/kernel/formatter.h
index ce015708d..d57134092 100644
--- a/src/kernel/formatter.h
+++ b/src/kernel/formatter.h
@@ -13,20 +13,6 @@ namespace lean {
 class expr;
 class environment;
 
-/** \brief Return true iff \c t contains a constant named \c n or a local constant with named (pp or not) \c n */
-bool is_used_name(expr const & t, name const & n);
-/**
-    \brief Return the body of the binding \c b, where variable #0 is replaced by a local constant with a "fresh" name.
-    The name is considered fresh if it is not used by a constant or local constant occuring in the body of \c b.
-    The fresh constant is also returned (second return value).
-
-    \remark If preserve_type is false, then the local constant will not use binding_domain.
-*/
-pair<expr, expr> binding_body_fresh(expr const & b, bool preserve_type = false);
-
-/** \brief Return the body of the let-expression \c l, where variable #0 is replaced by a local constant with a "fresh" name. */
-pair<expr, expr> let_body_fresh(expr const & l, bool preserve_type = false);
-
 class formatter {
     std::function<format(expr const &, options const &)> m_fn;
     options                             m_options;
@@ -40,8 +26,8 @@ public:
 typedef std::function<formatter(environment const &, options const &)> formatter_factory;
 
 std::ostream & operator<<(std::ostream & out, expr const & e);
-/** \brief Create a simple formatter object based on operator */
-formatter_factory mk_simple_formatter_factory();
 
 typedef std::function<format(formatter const &)> pp_fn;
+
+void set_print_fn(std::function<void(std::ostream &, expr const &)> const & fn);
 }
diff --git a/src/library/CMakeLists.txt b/src/library/CMakeLists.txt
index 838ab0bb0..2abb631dd 100644
--- a/src/library/CMakeLists.txt
+++ b/src/library/CMakeLists.txt
@@ -7,6 +7,7 @@ add_library(library deep_copy.cpp expr_lt.cpp io_state.cpp occurs.cpp
   standard_kernel.cpp hott_kernel.cpp sorry.cpp
   unifier.cpp unifier_plugin.cpp inductive_unifier_plugin.cpp
   explicit.cpp num.cpp string.cpp opaque_hints.cpp head_map.cpp
-  match.cpp definition_cache.cpp declaration_index.cpp)
+  match.cpp definition_cache.cpp declaration_index.cpp
+  simple_formatter.cpp)
 
 target_link_libraries(library ${LEAN_LIBS})
diff --git a/src/library/io_state.cpp b/src/library/io_state.cpp
index ce637ed4e..f313ab4a9 100644
--- a/src/library/io_state.cpp
+++ b/src/library/io_state.cpp
@@ -5,6 +5,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Author: Leonardo de Moura
 */
 #include "kernel/kernel_exception.h"
+#include "library/simple_formatter.h"
 #include "library/io_state.h"
 
 namespace lean {
diff --git a/src/library/kernel_bindings.cpp b/src/library/kernel_bindings.cpp
index 8414ad20d..2961b56dd 100644
--- a/src/library/kernel_bindings.cpp
+++ b/src/library/kernel_bindings.cpp
@@ -31,6 +31,7 @@ Author: Leonardo de Moura
 #include "library/normalize.h"
 #include "library/module.h"
 #include "library/opaque_hints.h"
+#include "library/simple_formatter.h"
 
 // Lua Bindings for the Kernel classes. We do not include the Lua
 // bindings in the kernel because we do not want to inflate the Kernel.
diff --git a/src/library/simple_formatter.cpp b/src/library/simple_formatter.cpp
new file mode 100644
index 000000000..ee39ed43d
--- /dev/null
+++ b/src/library/simple_formatter.cpp
@@ -0,0 +1,269 @@
+/*
+Copyright (c) 2014 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#include <utility>
+#include "kernel/formatter.h"
+#include "kernel/environment.h"
+#include "kernel/find_fn.h"
+#include "kernel/instantiate.h"
+#include "kernel/free_vars.h"
+#include "kernel/annotation.h"
+#include "library/simple_formatter.h"
+
+namespace lean {
+bool is_used_name(expr const & t, name const & n) {
+    return static_cast<bool>(
+        find(t, [&](expr const & e, unsigned) {
+                return (is_constant(e) && const_name(e) == n)  // t has a constant named n
+                    || (is_local(e) && (mlocal_name(e) == n || local_pp_name(e) == n)); // t has a local constant named n
+            }));
+}
+
+name pick_unused_name(expr const & t, name const & s) {
+    name r = s;
+    unsigned i = 1;
+    while (is_used_name(t, r)) {
+        r = name(s).append_after(i);
+        i++;
+    }
+    return r;
+}
+
+bool is_internal_name(name n) {
+    while (!n.is_atomic())
+        n = n.get_prefix();
+    return n.is_numeral();
+}
+
+static name g_x("x");
+pair<expr, expr> binding_body_fresh(expr const & b, bool preserve_type) {
+    lean_assert(is_binding(b));
+    name n = binding_name(b);
+    if (is_internal_name(n))
+        n = g_x;
+    n = pick_unused_name(binding_body(b), n);
+    expr c = mk_local(n, preserve_type ? binding_domain(b) : expr(), binding_info(b));
+    return mk_pair(instantiate(binding_body(b), c), c);
+}
+
+static name g_internal("M");
+name fix_internal_name(name const & a) {
+    if (a.is_atomic()) {
+        if (a.is_numeral())
+            return g_internal;
+        else
+            return a;
+    } else {
+        name p = fix_internal_name(a.get_prefix());
+        if (p == a.get_prefix())
+            return a;
+        else if (a.is_numeral())
+            return name(p, a.get_numeral());
+        else
+            return name(p, a.get_string());
+    }
+}
+
+/**
+   \brief Very basic printer for expressions.
+   It is mainly used when debugging code.
+*/
+struct print_expr_fn {
+    std::ostream & m_out;
+    bool m_type0_as_bool;
+
+    std::ostream & out() { return m_out; }
+
+    bool is_atomic(expr const & a) {
+        return ::lean::is_atomic(a) || is_mlocal(a);
+    }
+
+    void print_child(expr const & a) {
+        if (is_atomic(a)) {
+            print(a);
+        } else {
+            out() << "("; print(a); out() << ")";
+        }
+    }
+
+    bool print_let(expr const & a) {
+        if (!is_let_annotation(a))
+            return false;
+        expr l = get_annotation_arg(a);
+        if (!is_app(l) || !is_lambda(app_fn(l)))
+            return false;
+        name n = binding_name(app_fn(l));
+        expr t = binding_domain(app_fn(l));
+        expr b = binding_body(app_fn(l));
+        expr v = app_arg(l);
+        n      = pick_unused_name(b, n);
+        expr c = mk_local(n, expr());
+        b      = instantiate(b, c);
+        out() << "let " << c;
+        out() << " : ";
+        print(t);
+        out() << " := ";
+        print(v);
+        out() << " in ";
+        print_child(b);
+        return true;
+    }
+
+    void print_macro(expr const & a) {
+        if (!print_let(a)) {
+            macro_def(a).display(out());
+            for (unsigned i = 0; i < macro_num_args(a); i++) {
+                out() << " "; print_child(macro_arg(a, i));
+            }
+        }
+    }
+
+    void print_sort(expr const & a) {
+        if (is_zero(sort_level(a))) {
+            if (m_type0_as_bool)
+                out() << "Prop";
+            else
+                out() << "Type";
+        } else if (m_type0_as_bool && is_one(sort_level(a))) {
+            out() << "Type";
+        } else {
+            out() << "Type.{" << sort_level(a) << "}";
+        }
+    }
+
+    void print_app(expr const & e) {
+        expr const & f = app_fn(e);
+        if (is_app(f))
+            print(f);
+        else
+            print_child(f);
+        out() << " ";
+        print_child(app_arg(e));
+    }
+
+    void print_arrow_body(expr const & a) {
+        if (is_atomic(a) || is_arrow(a))
+            return print(a);
+        else
+            return print_child(a);
+    }
+
+    void print_binding(char const * bname, expr e) {
+        expr_kind k = e.kind();
+        out() << bname;
+        while (e.kind() == k) {
+            out() << " ";
+            auto p = binding_body_fresh(e);
+            expr const & n = p.second;
+            if (binding_info(e).is_implicit())
+                out() << "{";
+            else if (binding_info(e).is_cast())
+                out() << "[";
+            else if (!binding_info(e).is_contextual())
+                out() << "[[";
+            else if (binding_info(e).is_strict_implicit())
+                out() << "{{";
+            else
+                out() << "(";
+            out() << n << " : ";
+            print(binding_domain(e));
+            if (binding_info(e).is_implicit())
+                out() << "}";
+            else if (binding_info(e).is_cast())
+                out() << "]";
+            else if (!binding_info(e).is_contextual())
+                out() << "]]";
+            else if (binding_info(e).is_strict_implicit())
+                out() << "}}";
+            else
+                out() << ")";
+            e = p.first;
+        }
+        out() << ", ";
+        print_child(e);
+    }
+
+    void print_const(expr const & a) {
+        list<level> const & ls = const_levels(a);
+        out() << const_name(a);
+        if (!is_nil(ls)) {
+            out() << ".{";
+            bool first = true;
+            for (auto l : ls) {
+                if (first) first = false; else out() << " ";
+                if (is_max(l) || is_imax(l))
+                    out() << "(" << l << ")";
+                else
+                    out() << l;
+            }
+            out() << "}";
+        }
+    }
+
+    void print(expr const & a) {
+        switch (a.kind()) {
+        case expr_kind::Meta:
+            out() << "?" << fix_internal_name(mlocal_name(a));
+            break;
+        case expr_kind::Local:
+            out() << fix_internal_name(local_pp_name(a));
+            break;
+        case expr_kind::Var:
+            out() << "#" << var_idx(a);
+            break;
+        case expr_kind::Constant:
+            print_const(a);
+            break;
+        case expr_kind::App:
+            print_app(a);
+            break;
+        case expr_kind::Lambda:
+            print_binding("fun", a);
+            break;
+        case expr_kind::Pi:
+            if (!is_arrow(a)) {
+                print_binding("Pi", a);
+            } else {
+                print_child(binding_domain(a));
+                out() << " -> ";
+                print_arrow_body(lower_free_vars(binding_body(a), 1));
+            }
+            break;
+        case expr_kind::Sort:
+            print_sort(a);
+            break;
+        case expr_kind::Macro:
+            print_macro(a);
+            break;
+        }
+    }
+
+    print_expr_fn(std::ostream & out, bool type0_as_bool = true):m_out(out), m_type0_as_bool(type0_as_bool) {}
+
+    void operator()(expr const & e) {
+        scoped_expr_caching set(false);
+        print(e);
+    }
+};
+
+formatter_factory mk_simple_formatter_factory() {
+    return [](environment const & env, options const & o) { // NOLINT
+        return formatter(o, [=](expr const & e, options const &) {
+                std::ostringstream s;
+                print_expr_fn pr(s, env.prop_proof_irrel());
+                pr(e);
+                return format(s.str());
+            });
+    };
+}
+
+void init_default_print_fn() {
+    set_print_fn([](std::ostream & out, expr const & e) {
+            print_expr_fn pr(out);
+            pr(e);
+        });
+}
+}
diff --git a/src/library/simple_formatter.h b/src/library/simple_formatter.h
new file mode 100644
index 000000000..d63cba0e1
--- /dev/null
+++ b/src/library/simple_formatter.h
@@ -0,0 +1,30 @@
+/*
+Copyright (c) 2014 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#pragma once
+#include "kernel/formatter.h"
+
+namespace lean {
+/** \brief Return true iff \c t contains a constant named \c n or a local constant with named (pp or not) \c n */
+bool is_used_name(expr const & t, name const & n);
+/**
+    \brief Return the body of the binding \c b, where variable #0 is replaced by a local constant with a "fresh" name.
+    The name is considered fresh if it is not used by a constant or local constant occuring in the body of \c b.
+    The fresh constant is also returned (second return value).
+
+    \remark If preserve_type is false, then the local constant will not use binding_domain.
+*/
+pair<expr, expr> binding_body_fresh(expr const & b, bool preserve_type = false);
+
+/** \brief Return the body of the let-expression \c l, where variable #0 is replaced by a local constant with a "fresh" name. */
+pair<expr, expr> let_body_fresh(expr const & l, bool preserve_type = false);
+
+/** \brief Create a simple formatter object based on operator */
+formatter_factory mk_simple_formatter_factory();
+
+/** \brief Use simple formatter as the default print function */
+void init_default_print_fn();
+}
diff --git a/src/library/unifier.cpp b/src/library/unifier.cpp
index 02138dc98..0fed3cfcc 100644
--- a/src/library/unifier.cpp
+++ b/src/library/unifier.cpp
@@ -26,6 +26,7 @@ Author: Leonardo de Moura
 #include "library/opaque_hints.h"
 #include "library/unifier_plugin.h"
 #include "library/kernel_bindings.h"
+#include "library/simple_formatter.h"
 
 #ifndef LEAN_DEFAULT_UNIFIER_MAX_STEPS
 #define LEAN_DEFAULT_UNIFIER_MAX_STEPS 20000
diff --git a/src/shell/lean.cpp b/src/shell/lean.cpp
index 93f4d7a29..e362c5e10 100644
--- a/src/shell/lean.cpp
+++ b/src/shell/lean.cpp
@@ -26,6 +26,7 @@ Author: Leonardo de Moura
 #include "library/io_state_stream.h"
 #include "library/definition_cache.h"
 #include "library/declaration_index.h"
+#include "library/simple_formatter.h"
 #include "library/error_handling/error_handling.h"
 #include "frontends/lean/parser.h"
 #include "frontends/lean/pp.h"
@@ -150,6 +151,7 @@ public:
 
 int main(int argc, char ** argv) {
     lean::save_stack_info();
+    lean::init_default_print_fn();
     lean::register_modules();
     bool export_objects  = false;
     unsigned trust_lvl   = 0;
diff --git a/src/tests/kernel/CMakeLists.txt b/src/tests/kernel/CMakeLists.txt
index 76a20db2d..59464eee4 100644
--- a/src/tests/kernel/CMakeLists.txt
+++ b/src/tests/kernel/CMakeLists.txt
@@ -11,13 +11,13 @@ add_executable(free_vars free_vars.cpp)
 target_link_libraries(free_vars "kernel" "util" ${EXTRA_LIBS})
 add_test(free_vars ${CMAKE_CURRENT_BINARY_DIR}/free_vars)
 add_executable(replace replace.cpp)
-target_link_libraries(replace "kernel" "util" ${EXTRA_LIBS})
+target_link_libraries(replace "library"  "kernel" "util" ${EXTRA_LIBS})
 add_test(replace ${CMAKE_CURRENT_BINARY_DIR}/replace)
 add_executable(environment environment.cpp)
-target_link_libraries(environment "kernel" "util" ${EXTRA_LIBS})
+target_link_libraries(environment "library" "kernel" "util" ${EXTRA_LIBS})
 add_test(environment ${CMAKE_CURRENT_BINARY_DIR}/environment)
 add_executable(metavar metavar.cpp)
-target_link_libraries(metavar "kernel" "util" ${EXTRA_LIBS})
+target_link_libraries(metavar "library" "kernel" "util" ${EXTRA_LIBS})
 add_test(metavar ${CMAKE_CURRENT_BINARY_DIR}/metavar)
 add_executable(instantiate instantiate.cpp)
 target_link_libraries(instantiate "kernel" "util" ${EXTRA_LIBS})
diff --git a/src/tests/kernel/environment.cpp b/src/tests/kernel/environment.cpp
index 402817b84..cb334fc62 100644
--- a/src/tests/kernel/environment.cpp
+++ b/src/tests/kernel/environment.cpp
@@ -12,6 +12,7 @@ Author: Leonardo de Moura
 #include "kernel/type_checker.h"
 #include "kernel/abstract.h"
 #include "kernel/kernel_exception.h"
+#include "library/simple_formatter.cpp"
 using namespace lean;
 
 static environment add_decl(environment const & env, declaration const & d) {
@@ -243,6 +244,7 @@ public:
 
 int main() {
     save_stack_info();
+    init_default_print_fn();
     tst1();
     tst2();
     tst3();
diff --git a/src/tests/kernel/expr.cpp b/src/tests/kernel/expr.cpp
index 16107d0f4..f4338fdc1 100644
--- a/src/tests/kernel/expr.cpp
+++ b/src/tests/kernel/expr.cpp
@@ -16,6 +16,7 @@ Author: Leonardo de Moura
 #include "kernel/abstract.h"
 #include "kernel/instantiate.h"
 #include "library/max_sharing.h"
+#include "library/simple_formatter.h"
 #include "library/deep_copy.h"
 #include "library/kernel_serializer.h"
 using namespace lean;
@@ -362,6 +363,7 @@ static void tst18() {
 
 int main() {
     save_stack_info();
+    init_default_print_fn();
     lean_assert(sizeof(expr) == sizeof(optional<expr>));
     tst1();
     tst2();
diff --git a/src/tests/kernel/max_sharing.cpp b/src/tests/kernel/max_sharing.cpp
index 6ab383a74..ebe973546 100644
--- a/src/tests/kernel/max_sharing.cpp
+++ b/src/tests/kernel/max_sharing.cpp
@@ -6,8 +6,9 @@ Author: Leonardo de Moura
 */
 #include <iostream>
 #include "util/test.h"
-#include "library/max_sharing.h"
 #include "kernel/abstract.h"
+#include "library/max_sharing.h"
+#include "library/simple_formatter.h"
 using namespace lean;
 
 static void tst1() {
@@ -59,6 +60,7 @@ static void tst3() {
 
 int main() {
     save_stack_info();
+    init_default_print_fn();
     scoped_expr_caching set(false);
     tst1();
     tst2();
diff --git a/src/tests/kernel/metavar.cpp b/src/tests/kernel/metavar.cpp
index 9d92b409e..d653a8c88 100644
--- a/src/tests/kernel/metavar.cpp
+++ b/src/tests/kernel/metavar.cpp
@@ -14,6 +14,7 @@ Author: Leonardo de Moura
 #include "kernel/metavar.h"
 #include "kernel/instantiate.h"
 #include "kernel/abstract.h"
+#include "library/simple_formatter.h"
 using namespace lean;
 
 void collect_assumptions(justification const & j, buffer<unsigned> & r) {
@@ -145,6 +146,7 @@ static void tst4() {
 
 int main() {
     save_stack_info();
+    init_default_print_fn();
     tst1();
     tst2();
     tst3();
diff --git a/src/tests/kernel/replace.cpp b/src/tests/kernel/replace.cpp
index 78b11ca76..df895ad6c 100644
--- a/src/tests/kernel/replace.cpp
+++ b/src/tests/kernel/replace.cpp
@@ -11,6 +11,7 @@ Author: Leonardo de Moura
 #include "kernel/instantiate.h"
 #include "kernel/expr_maps.h"
 #include "kernel/replace_fn.h"
+#include "library/simple_formatter.h"
 using namespace lean;
 
 expr mk_big(expr f, unsigned depth, unsigned val) {
@@ -58,6 +59,7 @@ public:
 
 int main() {
     save_stack_info();
+    init_default_print_fn();
     tst1();
     tst2();
     std::cout << "done" << "\n";