diff --git a/src/interp/iz3scopes.cpp b/src/interp/iz3scopes.cpp
index 382779be0..198ecffe3 100755
--- a/src/interp/iz3scopes.cpp
+++ b/src/interp/iz3scopes.cpp
@@ -19,6 +19,8 @@ Revision History:
 
 #include <assert.h>
 
+#include <algorithm>
+
 #include "iz3scopes.h"