diff --git a/Stinger/Classes/STDefines.h b/Stinger/Classes/STDefines.h
index c4ab8bd..9c2cc25 100644
--- a/Stinger/Classes/STDefines.h
+++ b/Stinger/Classes/STDefines.h
@@ -75,6 +75,7 @@ typedef NS_ENUM(NSInteger, STHookResult) {
 @property (nonatomic, weak) Class hookedCls;
 @property (nonatomic, weak) Class statedCls;
 @property (nonatomic, assign) BOOL isInstanceHook;
+@property (nonatomic, assign) BOOL isInstanceIsaHook;
 
 + (instancetype)poolWithTypeEncoding:(NSString *)typeEncoding originalIMP:(IMP)imp selector:(SEL)sel;
 @end
diff --git a/Stinger/Classes/STHookInfoPool.m b/Stinger/Classes/STHookInfoPool.m
index 912d105..6770ca9 100644
--- a/Stinger/Classes/STHookInfoPool.m
+++ b/Stinger/Classes/STHookInfoPool.m
@@ -214,6 +214,7 @@ @implementation STHookInfoPool {
 @synthesize hookedCls = _hookedCls;
 @synthesize statedCls = _statedCls;
 @synthesize isInstanceHook = _isInstanceHook;
+@synthesize isInstanceIsaHook = _isInstanceIsaHook;
 @synthesize semaphore = _semaphore;
 
 
@@ -408,7 +409,9 @@ NS_INLINE void _st_ffi_function(ffi_cif *cif, void *ret, void **args, void *user
   void **slf = args[0];
   
   if (hookedClassInfoPool->_isInstanceHook) {
-    statedClassInfoPool = _st_fast_get_HookInfoPool(hookedClassInfoPool->_statedCls, hookedClassInfoPool->_uniqueKey);
+    if (!hookedClassInfoPool->_isInstanceIsaHook) {
+      statedClassInfoPool = _st_fast_get_HookInfoPool(hookedClassInfoPool->_statedCls, hookedClassInfoPool->_uniqueKey);
+    }
     instanceInfoPool = _st_fast_get_HookInfoPool((__bridge id)(*slf), hookedClassInfoPool->_uniqueKey);
   }
 
diff --git a/Stinger/Classes/Stinger.m b/Stinger/Classes/Stinger.m
index d345349..239ed0a 100644
--- a/Stinger/Classes/Stinger.m
+++ b/Stinger/Classes/Stinger.m
@@ -18,11 +18,11 @@ @implementation NSObject (Stinger)
 #pragma mark - For specific class
 
 + (STHookResult)st_hookInstanceMethod:(SEL)sel option:(STOption)option usingIdentifier:(STIdentifier)identifier withBlock:(id)block {
-  return hookMethod(self, sel, option, identifier, block);
+  return hookMethod(self, sel, option, identifier, block, NO);
 }
 
 + (STHookResult)st_hookClassMethod:(SEL)sel option:(STOption)option usingIdentifier:(STIdentifier)identifier withBlock:(id)block {
-  return hookMethod(object_getClass(self), sel, option, identifier, block);
+  return hookMethod(object_getClass(self), sel, option, identifier, block, NO);
 }
 
 + (NSArray<STIdentifier> *)st_allIdentifiersForKey:(SEL)key {
@@ -56,7 +56,7 @@ - (STHookResult)st_hookInstanceMethod:(SEL)sel option:(STOption)option usingIden
     Class stSubClass = getSTSubClass(self);
     if (!stSubClass) return STHookResultOther;
     
-    STHookResult hookMethodResult = hookMethod(stSubClass, sel, option, identifier, block);
+    STHookResult hookMethodResult = hookMethod(stSubClass, sel, option, identifier, block, YES);
     if (hookMethodResult != STHookResultSuccess) return hookMethodResult;
     if (!objc_getAssociatedObject(self, STSubClassKey)) {
       object_setClass(self, stSubClass);
@@ -91,7 +91,7 @@ - (BOOL)st_removeHookWithIdentifier:(STIdentifier)identifier forKey:(SEL)key {
 
 #pragma mark - inline functions
 
-NS_INLINE STHookResult hookMethod(Class hookedCls, SEL sel, STOption option, STIdentifier identifier, id block) {
+NS_INLINE STHookResult hookMethod(Class hookedCls, SEL sel, STOption option, STIdentifier identifier, id block, BOOL byInstanceHook) {
   NSCParameterAssert(hookedCls);
   NSCParameterAssert(sel);
   NSCParameterAssert(identifier);
@@ -124,11 +124,13 @@ NS_INLINE STHookResult hookMethod(Class hookedCls, SEL sel, STOption option, STI
       st_setHookInfoPool(hookedCls, sel, hookInfoPool);
     }
     if (st_isIntanceHookCls(hookedCls)) {
-      return STHookResultSuccess;
-    } else {
-      STHookInfo *hookInfo = [STHookInfo infoWithOption:option withIdentifier:identifier withBlock:block];
-      return [hookInfoPool addInfo:hookInfo] ? STHookResultSuccess :  STHookResultErrorIDExisted;
+      if (byInstanceHook) {
+        return STHookResultSuccess;
+      }
+      hookInfoPool.isInstanceIsaHook = YES;
     }
+    STHookInfo *hookInfo = [STHookInfo infoWithOption:option withIdentifier:identifier withBlock:block];
+    return [hookInfoPool addInfo:hookInfo] ? STHookResultSuccess : STHookResultErrorIDExisted;
   }
 }