diff --git a/src/screen.c b/src/screen.c
index 86ebd40..233d6a5 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -465,7 +465,8 @@
     // double-wide character. Clear the left half to avoid it getting the popup
     // window background color.
     if (coloff > 0 && ScreenLines[off_to] == 0
-					     && ScreenLinesUC[off_to - 1] != 0)
+		   && ScreenLinesUC[off_to - 1] != 0
+		   && (*mb_char2cells)(ScreenLinesUC[off_to - 1]) > 1)
     {
 	ScreenLines[off_to - 1] = ' ';
 	ScreenLinesUC[off_to - 1] = 0;