diff --git a/src/scanner.c b/src/scanner.c
index 80c466e2..b6c8a8d9 100644
--- a/src/scanner.c
+++ b/src/scanner.c
@@ -409,7 +409,7 @@ start_element(void *data, const char *element_name, const char **atts)
 		}
 
 		if (version < ctx->interface->since)
-			fail(&ctx->loc, "since version not increasing\n");
+			warn(&ctx->loc, "since version not increasing\n");
 		ctx->interface->since = version;
 		message->since = version;