diff --git a/common/src/main/java/com/highgo/cloud/util/CommonUtil.java b/common/src/main/java/com/highgo/cloud/util/CommonUtil.java
index 237f091..b668c0d 100644
--- a/common/src/main/java/com/highgo/cloud/util/CommonUtil.java
+++ b/common/src/main/java/com/highgo/cloud/util/CommonUtil.java
@@ -95,7 +95,7 @@ public static boolean isWrapClass(Class clz) {
 
     @SuppressWarnings("rawtypes")
     public static boolean isNumber(Class cls) {
-        return cls.getSuperclass().equals(Number.class) || CommonUtil.isWrapClass(cls) || cls.isPrimitive();
+        return Number.class.equals(cls.getSuperclass()) || CommonUtil.isWrapClass(cls) || cls.isPrimitive();
     }
 
     /**
diff --git a/tests/regression/CommonUtilClassPredicateRegression.java b/tests/regression/CommonUtilClassPredicateRegression.java
new file mode 100644
index 0000000..75dc59c
--- /dev/null
+++ b/tests/regression/CommonUtilClassPredicateRegression.java
@@ -0,0 +1,39 @@
+import com.highgo.cloud.util.CommonUtil;
+
+/** Complete real class, genuine JDK Class values, no copied classifier or framework doubles. */
+public final class CommonUtilClassPredicateRegression {
+    private static int failures;
+    private static int cases;
+
+    private static void expect(Class<?> type, boolean expected) {
+        cases++;
+        try {
+            boolean actual = CommonUtil.isNumber(type);
+            if (actual != expected) {
+                throw new AssertionError(type + ": expected " + expected + ", got " + actual);
+            }
+            System.out.println("PASS " + type.getTypeName());
+        } catch (Throwable error) {
+            failures++;
+            System.err.println("FAIL " + type.getTypeName() + ": " + error);
+            error.printStackTrace(System.err);
+        }
+    }
+
+    public static void main(String[] args) {
+        expect(byte.class, true);
+        expect(short.class, true);
+        expect(int.class, true);
+        expect(long.class, true);
+        expect(float.class, true);
+        expect(double.class, true);
+        expect(Object.class, false);
+        expect(CharSequence.class, false);
+        expect(Integer.class, true);
+        expect(String.class, false);
+        if (failures != 0) {
+            throw new AssertionError(failures + " of " + cases + " cases failed");
+        }
+        System.out.println(cases + " cases passed");
+    }
+}