diff --git a/testdata/parser/negative/19.pdl b/testdata/parser/negative/19.pdl
new file mode 100644
index 0000000000000000000000000000000000000000..66a30eed35ce366e127cde061aefad4d89bc8336
--- /dev/null
+++ b/testdata/parser/negative/19.pdl
@@ -0,0 +1,13 @@
+#version 100
+
+primitive main(in a) {
+	while (true) {
+		synchronous {
+			if (fires(a)) {
+				return 5;
+			} else {
+				block(a);
+			}
+		}
+	}
+}
\ No newline at end of file