diff --git a/Include/osdefs.h b/Include/osdefs.h
index e4ac74e..f914919 100644
--- a/Include/osdefs.h
+++ b/Include/osdefs.h
@@ -44,7 +44,7 @@
 #define DELIM '\n'
 #endif
 
-#if defined(MS_WINDOWS) || defined(__BORLANDC__) || defined(__WATCOMC__) ||  defined(__DJGPP__)
+#if defined(MS_WINDOWS) || defined(__BORLANDC__) || defined(__WATCOMC__) || defined(__DJGPP__) || defined(__TOS_OS2__)
 #define SEP '\\'
 #define ALTSEP '/'
 #define MAXPATHLEN 256