diff --git a/src/common/filename.cpp b/src/common/filename.cpp
index 307018d906..5a125fcd3f 100644
--- a/src/common/filename.cpp
+++ b/src/common/filename.cpp
@@ -135,6 +135,7 @@
 #endif
 
 #ifdef __EMX__
+#include <os2.h>
 #define MAX_PATH _MAX_PATH
 #endif