diff --git a/src/numerics/mpq.cpp b/src/numerics/mpq.cpp
index e0d3a235c..90dad4f9a 100644
--- a/src/numerics/mpq.cpp
+++ b/src/numerics/mpq.cpp
@@ -59,6 +59,12 @@ mpz ceil(mpq const & a) {
     return r;
 }
 
+void power(mpq & a, mpq const & b, unsigned k) {
+    mpz_pow_ui(mpq_numref(a.m_val), mpq_numref(b.m_val), k);
+    mpz_pow_ui(mpq_denref(a.m_val), mpq_denref(b.m_val), k);
+    mpq_canonicalize(a.m_val);
+}
+
 extern void display(std::ostream & out, __mpz_struct const * v);
 
 std::ostream & operator<<(std::ostream & out, mpq const & v) {
diff --git a/src/numerics/mpq.h b/src/numerics/mpq.h
index 396e88f65..af388417a 100644
--- a/src/numerics/mpq.h
+++ b/src/numerics/mpq.h
@@ -194,6 +194,9 @@ public:
     void ceil();
     friend mpz ceil(mpq const & a);
 
+    friend void power(mpq & a, mpq const & b, unsigned k);
+    friend mpq power(mpq a, unsigned k) { power(a, a, k); return a; }
+
     friend std::ostream & operator<<(std::ostream & out, mpq const & v);
 
     friend void display_decimal(std::ostream & out, mpq const & a, unsigned prec);