diff --git a/src/modal.c b/src/modal.c
index 76eaab9..5277c35 100644
--- a/src/modal.c
+++ b/src/modal.c
@@ -91,7 +91,7 @@ put_reg(char r)
 		} else
 			while(s < ss) *outp_++ = *s++;
 	} else
-		*outp_++ = r;
+		*outp_++ = '?', *outp_++ = r;
 }
 
 static char *