diff --git a/tests/test_modifier.cpp b/tests/test_modifier.cpp
index 5a2ed0d..2835481 100644
--- a/tests/test_modifier.cpp
+++ b/tests/test_modifier.cpp
@@ -3,7 +3,7 @@
 #ifdef _MSC_VER
 #define _USE_MATH_DEFINES
 #endif
-#include <math.h>
+#include <cmath>
 #include "lensfun.h"
 
 typedef struct {