diff --git a/scripts/mk_util.py b/scripts/mk_util.py
index 205b8f948..875cf449f 100644
--- a/scripts/mk_util.py
+++ b/scripts/mk_util.py
@@ -1617,8 +1617,11 @@ PYG_GLOBALS = { 'UINT' : UINT, 'BOOL' : BOOL, 'DOUBLE' : DOUBLE, 'STRING' : STRI
                 'def_module_params' : def_module_params }
 
 def _execfile(file, globals=globals(), locals=locals()):
-    with open(file, "r") as fh:
-        exec(fh.read()+"\n", globals, locals)
+    if sys.version < "2.7":
+        execfile(file, globals, locals)
+    else:
+        with open(file, "r") as fh:
+            exec(fh.read()+"\n", globals, locals)
 
 # Execute python auxiliary scripts that generate extra code for Z3.
 def exec_pyg_scripts():
diff --git a/src/math/realclosure/mpz_matrix.cpp b/src/math/realclosure/mpz_matrix.cpp
index ba89dfb36..799a5817e 100644
--- a/src/math/realclosure/mpz_matrix.cpp
+++ b/src/math/realclosure/mpz_matrix.cpp
@@ -75,14 +75,14 @@ void mpz_matrix_manager::set(mpz_matrix & A, mpz_matrix const & B) {
 }
 
 void mpz_matrix_manager::tensor_product(mpz_matrix const & A, mpz_matrix const & B, mpz_matrix & C) {
-    scoped_mpz_matrix _C(*this);
-    mk(A.m * B.m, A.n * B.n, _C);
-    for (unsigned i = 0; i < _C.m(); i++)
-        for (unsigned j = 0; j < _C.n(); j++)
+    scoped_mpz_matrix CC(*this);
+    mk(A.m * B.m, A.n * B.n, CC);
+    for (unsigned i = 0; i < CC.m(); i++)
+        for (unsigned j = 0; j < CC.n(); j++)
             nm().mul(A(i / B.m, j / B.n), 
                      B(i % B.m, j % B.n), 
-                     _C(i, j));
-    C.swap(_C);
+                     CC(i, j));
+    C.swap(CC);
 }
 
 void mpz_matrix_manager::swap_rows(mpz_matrix & A, unsigned i, unsigned j) {