diff --git a/src/frontends/lean/decl_cmds.cpp b/src/frontends/lean/decl_cmds.cpp
index 0b57cf476..332552b3e 100644
--- a/src/frontends/lean/decl_cmds.cpp
+++ b/src/frontends/lean/decl_cmds.cpp
@@ -286,7 +286,7 @@ struct decl_attributes {
     optional<unsigned> m_priority;
     optional<unsigned> m_unfold_c_hint;
 
-    decl_attributes(bool def_only = true, bool is_abbrev=false):m_priority() {
+    decl_attributes(bool def_only = true, bool is_abbrev = false):m_priority() {
         m_def_only               = def_only;
         m_is_abbrev              = is_abbrev;
         m_is_instance            = false;
diff --git a/src/library/abbreviation.cpp b/src/library/abbreviation.cpp
index 1c5572a3a..abbae5ca8 100644
--- a/src/library/abbreviation.cpp
+++ b/src/library/abbreviation.cpp
@@ -4,6 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 
 Author: Leonardo de Moura
 */
+#include <string>
 #include "util/sstream.h"
 #include "kernel/find_fn.h"
 #include "kernel/replace_fn.h"