diff --git a/awkgram.y b/awkgram.y
index 2c1555b..30bc52c 100644
--- a/awkgram.y
+++ b/awkgram.y
@@ -3097,6 +3097,7 @@ check_bad_char(int c)
 static int
 nextc(bool check_for_bad)
 {
+#define NO_CONTINUE_SOURCE_STRINGS
 	if (gawk_mb_cur_max > 1) {
 again:
 #ifdef NO_CONTINUE_SOURCE_STRINGS