diff --git a/mp/src/utils/vbsp/map.cpp b/mp/src/utils/vbsp/map.cpp
index a5456c32..2221c79f 100644
--- a/mp/src/utils/vbsp/map.cpp
+++ b/mp/src/utils/vbsp/map.cpp
@@ -2003,7 +2003,7 @@ void CMapFile::CheckForInstances( const char *pszFileName )
 	char	FDGPath[ MAX_PATH ];
 	if ( !g_pFullFileSystem->RelativePathToFullPath( GameDataFile, "EXECUTABLE_PATH", FDGPath, sizeof( FDGPath ) ) )
 	{
-		if ( !g_pFullFileSystem->RelativePathToFullPath( GameDataFile, "", FDGPath, sizeof( FDGPath ) ) )
+		if ( !g_pFullFileSystem->RelativePathToFullPath( GameDataFile, NULL, FDGPath, sizeof( FDGPath ) ) )
 		{
 			Msg( "Could not locate GameData file %s\n", GameDataFile );
 		}
diff --git a/sp/src/utils/vbsp/map.cpp b/sp/src/utils/vbsp/map.cpp
index a5456c32..2221c79f 100644
--- a/sp/src/utils/vbsp/map.cpp
+++ b/sp/src/utils/vbsp/map.cpp
@@ -2003,7 +2003,7 @@ void CMapFile::CheckForInstances( const char *pszFileName )
 	char	FDGPath[ MAX_PATH ];
 	if ( !g_pFullFileSystem->RelativePathToFullPath( GameDataFile, "EXECUTABLE_PATH", FDGPath, sizeof( FDGPath ) ) )
 	{
-		if ( !g_pFullFileSystem->RelativePathToFullPath( GameDataFile, "", FDGPath, sizeof( FDGPath ) ) )
+		if ( !g_pFullFileSystem->RelativePathToFullPath( GameDataFile, NULL, FDGPath, sizeof( FDGPath ) ) )
 		{
 			Msg( "Could not locate GameData file %s\n", GameDataFile );
 		}