diff --git a/code/sys/sys_win32.c b/code/sys/sys_win32.c
index 6979dce9..ee026bd8 100644
--- a/code/sys/sys_win32.c
+++ b/code/sys/sys_win32.c
@@ -357,6 +357,14 @@ Sys_FOpen
 ==============
 */
 FILE *Sys_FOpen( const char *ospath, const char *mode ) {
+	size_t length;
+
+	// Windows API ignores all trailing spaces and periods which can get around Quake 3 file system restrictions.
+	length = strlen( ospath );
+	if ( length == 0 || ospath[length-1] == ' ' || ospath[length-1] == '.' ) {
+		return NULL;
+	}
+
 	return fopen( ospath, mode );
 }