diff --git a/libasn1compiler/asn1c_constraint.c b/libasn1compiler/asn1c_constraint.c
index b7b7581..22b6543 100644
--- a/libasn1compiler/asn1c_constraint.c
+++ b/libasn1compiler/asn1c_constraint.c
@@ -168,7 +168,7 @@
 	OUT(") {\n");
 		INDENT(+1);
 		OUT("/* Constraint check succeeded */\n");
-		OUT("return 1;\n");
+		OUT("return 0;\n");
 		INDENT(-1);
 	OUT("} else {\n");
 		INDENT(+1);