diff --git a/src/fileio.cpp b/src/fileio.cpp
index 6b8173ccec..9f0db9e652 100644
--- a/src/fileio.cpp
+++ b/src/fileio.cpp
@@ -1121,7 +1121,7 @@ void DetermineBasePaths(const char *exe)
 		}
 	}
 
-#if defined(DOS) || defined(OS2)
+#if !defined(GLOBAL_DATA_DIR)
 	_searchpaths[SP_INSTALLATION_DIR] = NULL;
 #else
 	seprintf(tmp, lastof(tmp), "%s", GLOBAL_DATA_DIR);