diff --git a/TMCache/TMDiskCache.m b/TMCache/TMDiskCache.m
index a775316..52d4873 100644
--- a/TMCache/TMDiskCache.m
+++ b/TMCache/TMDiskCache.m
@@ -862,7 +862,7 @@ - (TMDiskCacheObjectBlock)willAddObjectBlock
     __block TMDiskCacheObjectBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _willAddObjectBlock;
+        block = self->_willAddObjectBlock;
     });
 
     return block;
@@ -886,7 +886,7 @@ - (TMDiskCacheObjectBlock)willRemoveObjectBlock
     __block TMDiskCacheObjectBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _willRemoveObjectBlock;
+        block = self->_willRemoveObjectBlock;
     });
 
     return block;
@@ -910,7 +910,7 @@ - (TMDiskCacheBlock)willRemoveAllObjectsBlock
     __block TMDiskCacheBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _willRemoveAllObjectsBlock;
+        block = self->_willRemoveAllObjectsBlock;
     });
 
     return block;
@@ -934,7 +934,7 @@ - (TMDiskCacheObjectBlock)didAddObjectBlock
     __block TMDiskCacheObjectBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _didAddObjectBlock;
+        block = self->_didAddObjectBlock;
     });
 
     return block;
@@ -958,7 +958,7 @@ - (TMDiskCacheObjectBlock)didRemoveObjectBlock
     __block TMDiskCacheObjectBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _didRemoveObjectBlock;
+        block = self->_didRemoveObjectBlock;
     });
 
     return block;
@@ -982,7 +982,7 @@ - (TMDiskCacheBlock)didRemoveAllObjectsBlock
     __block TMDiskCacheBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _didRemoveAllObjectsBlock;
+        block = self->_didRemoveAllObjectsBlock;
     });
 
     return block;
@@ -1006,7 +1006,7 @@ - (NSUInteger)byteLimit
     __block NSUInteger byteLimit = 0;
     
     dispatch_sync(_queue, ^{
-        byteLimit = _byteLimit;
+        byteLimit = self->_byteLimit;
     });
     
     return byteLimit;
@@ -1033,7 +1033,7 @@ - (NSTimeInterval)ageLimit
     __block NSTimeInterval ageLimit = 0.0;
     
     dispatch_sync(_queue, ^{
-        ageLimit = _ageLimit;
+        ageLimit = self->_ageLimit;
     });
     
     return ageLimit;
diff --git a/TMCache/TMMemoryCache.m b/TMCache/TMMemoryCache.m
index 17c56a4..419eb80 100644
--- a/TMCache/TMMemoryCache.m
+++ b/TMCache/TMMemoryCache.m
@@ -290,7 +290,7 @@ - (void)setObject:(id)object forKey:(NSString *)key withCost:(NSUInteger)cost bl
         [strongSelf->_dates setObject:now forKey:key];
         [strongSelf->_costs setObject:@(cost) forKey:key];
 
-        _totalCost += cost;
+        strongSelf->_totalCost += cost;
 
         if (strongSelf->_didAddObjectBlock)
             strongSelf->_didAddObjectBlock(strongSelf, key, object);
@@ -652,7 +652,7 @@ - (TMMemoryCacheObjectBlock)willRemoveObjectBlock
     __block TMMemoryCacheObjectBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _willRemoveObjectBlock;
+        block = self->_willRemoveObjectBlock;
     });
 
     return block;
@@ -676,7 +676,7 @@ - (TMMemoryCacheBlock)willRemoveAllObjectsBlock
     __block TMMemoryCacheBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _willRemoveAllObjectsBlock;
+        block = self->_willRemoveAllObjectsBlock;
     });
 
     return block;
@@ -700,7 +700,7 @@ - (TMMemoryCacheObjectBlock)didAddObjectBlock
     __block TMMemoryCacheObjectBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _didAddObjectBlock;
+        block = self->_didAddObjectBlock;
     });
 
     return block;
@@ -724,7 +724,7 @@ - (TMMemoryCacheObjectBlock)didRemoveObjectBlock
     __block TMMemoryCacheObjectBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _didRemoveObjectBlock;
+        block = self->_didRemoveObjectBlock;
     });
 
     return block;
@@ -748,7 +748,7 @@ - (TMMemoryCacheBlock)didRemoveAllObjectsBlock
     __block TMMemoryCacheBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _didRemoveAllObjectsBlock;
+        block = self->_didRemoveAllObjectsBlock;
     });
 
     return block;
@@ -772,7 +772,7 @@ - (TMMemoryCacheBlock)didReceiveMemoryWarningBlock
     __block TMMemoryCacheBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _didReceiveMemoryWarningBlock;
+        block = self->_didReceiveMemoryWarningBlock;
     });
 
     return block;
@@ -796,7 +796,7 @@ - (TMMemoryCacheBlock)didEnterBackgroundBlock
     __block TMMemoryCacheBlock block = nil;
 
     dispatch_sync(_queue, ^{
-        block = _didEnterBackgroundBlock;
+        block = self->_didEnterBackgroundBlock;
     });
 
     return block;
@@ -820,7 +820,7 @@ - (NSTimeInterval)ageLimit
     __block NSTimeInterval ageLimit = 0.0;
     
     dispatch_sync(_queue, ^{
-        ageLimit = _ageLimit;
+        ageLimit = self->_ageLimit;
     });
     
     return ageLimit;
@@ -846,7 +846,7 @@ - (NSUInteger)costLimit
     __block NSUInteger costLimit = 0;
 
     dispatch_sync(_queue, ^{
-        costLimit = _costLimit;
+        costLimit = self->_costLimit;
     });
 
     return costLimit;
@@ -873,7 +873,7 @@ - (NSUInteger)totalCost
     __block NSUInteger cost = 0;
     
     dispatch_sync(_queue, ^{
-        cost = _totalCost;
+        cost = self->_totalCost;
     });
     
     return cost;