diff --git a/SDWebImage/Core/SDImageCache.h b/SDWebImage/Core/SDImageCache.h
index 0289b920..3cf9168b 100644
--- a/SDWebImage/Core/SDImageCache.h
+++ b/SDWebImage/Core/SDImageCache.h
@@ -323,6 +323,7 @@ typedef NS_OPTIONS(NSUInteger, SDImageCacheOptions) {
  * @param doneBlock The completion block. Will not get called if the operation is cancelled
  *
  * @return a SDImageCacheToken instance containing the cache operation, will callback immediately when cancelled
+ * @warning If you query with thumbnail cache key, you'd better not pass the thumbnail pixel size context, which is undefined behavior.
  */
 - (nullable SDImageCacheToken *)queryCacheOperationForKey:(nullable NSString *)key options:(SDImageCacheOptions)options done:(nullable SDImageCacheQueryCompletionBlock)doneBlock;
 
@@ -335,6 +336,7 @@ typedef NS_OPTIONS(NSUInteger, SDImageCacheOptions) {
  * @param doneBlock The completion block. Will not get called if the operation is cancelled
  *
  * @return a SDImageCacheToken instance containing the cache operation, will callback immediately when cancellederation, will callback immediately when cancelled
+ * @warning If you query with thumbnail cache key, you'd better not pass the thumbnail pixel size context, which is undefined behavior.
  */
 - (nullable SDImageCacheToken *)queryCacheOperationForKey:(nullable NSString *)key options:(SDImageCacheOptions)options context:(nullable SDWebImageContext *)context done:(nullable SDImageCacheQueryCompletionBlock)doneBlock;
 
@@ -348,6 +350,7 @@ typedef NS_OPTIONS(NSUInteger, SDImageCacheOptions) {
  * @param doneBlock The completion block. Will not get called if the operation is cancelled
  *
  * @return a SDImageCacheToken instance containing the cache operation, will callback immediately when cancelled
+ * @warning If you query with thumbnail cache key, you'd better not pass the thumbnail pixel size context, which is undefined behavior.
  */
 - (nullable SDImageCacheToken *)queryCacheOperationForKey:(nullable NSString *)key options:(SDImageCacheOptions)options context:(nullable SDWebImageContext *)context cacheType:(SDImageCacheType)queryCacheType done:(nullable SDImageCacheQueryCompletionBlock)doneBlock;
 
diff --git a/SDWebImage/Core/SDImageCache.m b/SDWebImage/Core/SDImageCache.m
index c188adc3..84b27c30 100644
--- a/SDWebImage/Core/SDImageCache.m
+++ b/SDWebImage/Core/SDImageCache.m
@@ -533,8 +533,7 @@ static NSString * _defaultDiskCacheDirectory;
     // The disk -> memory sync logic, which should only store thumbnail image with thumbnail key
     // However, caller (like SDWebImageManager) will query full key, with thumbnail size, and get thubmnail image
     // We should add a check here, currently it's a hack
-    if (diskImage.sd_isThumbnail) {
-        NSAssert(!SDIsThumbnailKey(key), @"The input cache key %@ should not be thumbnail key", key);
+    if (diskImage.sd_isThumbnail && !SDIsThumbnailKey(key)) {
         SDImageCoderOptions *options = diskImage.sd_decodeOptions;
         CGSize thumbnailSize = CGSizeZero;
         NSValue *thumbnailSizeValue = options[SDImageCoderDecodeThumbnailPixelSize];