diff --git a/t/pt-config-diff/samples/case1.cnf b/t/pt-config-diff/samples/case1.cnf
new file mode 100644
index 00000000..9b431bf2
--- /dev/null
+++ b/t/pt-config-diff/samples/case1.cnf
@@ -0,0 +1,2 @@
+[mysqld]
+binlog_format = genlog
diff --git a/t/pt-config-diff/samples/case2.cnf b/t/pt-config-diff/samples/case2.cnf
new file mode 100644
index 00000000..d8563ddc
--- /dev/null
+++ b/t/pt-config-diff/samples/case2.cnf
@@ -0,0 +1,2 @@
+[mysqld]
+binlog_format = GENLOG