diff --git a/src/regexp.c b/src/regexp.c
index 842c480..b15dc3a 100644
--- a/src/regexp.c
+++ b/src/regexp.c
@@ -2125,7 +2125,7 @@
 		// Execute instructions from ISN_SUBSTITUTE.
 		eval_result[nested] = exe_substitute_instr();
 	    else
-		eval_result[nested] = eval_to_string(source + 2, TRUE);
+		eval_result[nested] = eval_to_string(source + 2, TRUE, FALSE);
 	    --nesting;
 
 	    if (eval_result[nested] != NULL)