diff --git a/fizz-core/src/test/java/we/fizz/function/StringFuncTests.java b/fizz-core/src/test/java/we/fizz/function/StringFuncTests.java
index 7062986..79f0962 100644
--- a/fizz-core/src/test/java/we/fizz/function/StringFuncTests.java
+++ b/fizz-core/src/test/java/we/fizz/function/StringFuncTests.java
@@ -52,6 +52,13 @@ class StringFuncTests {
 		assertEquals("2021-07-09 22:44:55yyyy-MM-dd HH:mm:ss", result.toString());
 	}
 	
+	@Test
+	void testConcat3() {
+		String funcExpression = "fn.string.concat(\"2021-07-09 22:44:55\", \"yyyy-MM-dd HH:mm:ss\",1)";
+		Object result = FuncExecutor.getInstance().exec(null, funcExpression);
+		assertEquals("2021-07-09 22:44:55yyyy-MM-dd HH:mm:ss1", result.toString());
+	}
+	
 	@Test
 	void testConcatws() {
 		String funcExpression = "fn.string.concatws(\",\" ,  \"2021-07-09 22:44:55\", \"yyyy-MM-dd HH:mm:ss\")";