diff --git a/src/screenshot.c b/src/screenshot.c
index 0720f03..76a7480 100644
--- a/src/screenshot.c
+++ b/src/screenshot.c
@@ -133,7 +133,7 @@ BOOL ss_take_screenshot(IDirectDrawSurfaceImpl* src)
     }
 
     strftime(str_time, sizeof(str_time), "%Y-%m-%d_%H-%M-%S", localtime(&t));
-    _snprintf(filename, sizeof(filename), "%s-%s.png", title, str_time);
+    _snprintf(filename, sizeof(filename), "%s_%s.png", title, str_time);
 
     if (src->bpp == 8 && src->palette)
     {