diff --git a/src/test/ex.cpp b/src/test/ex.cpp
index 276d21cab..e9243dd5b 100644
--- a/src/test/ex.cpp
+++ b/src/test/ex.cpp
@@ -54,7 +54,7 @@ static void tst1() {
 
 static void tst2() {
     try {
-        throw default_exception("Format %d %s", 12, "twelve");
+        throw default_exception(default_exception::fmt(), "Format %d %s", 12, "twelve");
     }
     catch (z3_exception& ex) {
         std::cerr << ex.msg() << "\n";