diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 88c92623d..887836cf3 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -32,7 +32,7 @@
 #include <string>
 #include <utility>
 #include <vector>
-#include <cctype>
+#include <cstdint>
 
 class TestValueFlow : public TestFixture {
 public: