diff --git a/src/common/filename.cpp b/src/common/filename.cpp
index 61e1d1bfbe..05d484737d 100644
--- a/src/common/filename.cpp
+++ b/src/common/filename.cpp
@@ -125,6 +125,7 @@
 #endif
 
 #ifdef __EMX__
+#include <os2.h>
 #define MAX_PATH _MAX_PATH
 #endif