diff --git a/.gitignore b/.gitignore
index 718941c..e71f35b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,4 +27,5 @@ nuget.exe
 project.lock.json
 /.vs/
 .build/
-.testPublish/
\ No newline at end of file
+.testPublish/
+launchSettings.json
\ No newline at end of file
diff --git a/src/Microsoft.AspNetCore.ResponseCaching/Internal/MemoryResponseCacheStore.cs b/src/Microsoft.AspNetCore.ResponseCaching/Internal/MemoryResponseCacheStore.cs
index 1a49f19..02191c9 100644
--- a/src/Microsoft.AspNetCore.ResponseCaching/Internal/MemoryResponseCacheStore.cs
+++ b/src/Microsoft.AspNetCore.ResponseCaching/Internal/MemoryResponseCacheStore.cs
@@ -24,11 +24,11 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
         public Task<IResponseCacheEntry> GetAsync(string key)
         {
             var entry = _cache.Get(key);
-
-            if (entry is MemoryCachedResponse)
+            
+            var memoryCachedResponse = entry as MemoryCachedResponse;
+            if (memoryCachedResponse != null)
             {
-                var memoryCachedResponse = (MemoryCachedResponse)entry;
-                return Task.FromResult<IResponseCacheEntry>(new CachedResponse()
+                return Task.FromResult<IResponseCacheEntry>(new CachedResponse
                 {
                     Created = memoryCachedResponse.Created,
                     StatusCode = memoryCachedResponse.StatusCode,
@@ -44,15 +44,15 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
 
         public async Task SetAsync(string key, IResponseCacheEntry entry, TimeSpan validFor)
         {
-            if (entry is CachedResponse)
+            var cachedResponse = entry as CachedResponse;
+            if (cachedResponse != null)
             {
-                var cachedResponse = (CachedResponse)entry;
                 var segmentStream = new SegmentWriteStream(StreamUtilities.BodySegmentSize);
                 await cachedResponse.Body.CopyToAsync(segmentStream);
 
                 _cache.Set(
                     key,
-                    new MemoryCachedResponse()
+                    new MemoryCachedResponse
                     {
                         Created = cachedResponse.Created,
                         StatusCode = cachedResponse.StatusCode,
@@ -60,7 +60,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
                         BodySegments = segmentStream.GetSegments(),
                         BodyLength = segmentStream.Length
                     },
-                    new MemoryCacheEntryOptions()
+                    new MemoryCacheEntryOptions
                     {
                         AbsoluteExpirationRelativeToNow = validFor
                     });
@@ -70,7 +70,7 @@ namespace Microsoft.AspNetCore.ResponseCaching.Internal
                 _cache.Set(
                     key,
                     entry,
-                    new MemoryCacheEntryOptions()
+                    new MemoryCacheEntryOptions
                     {
                         AbsoluteExpirationRelativeToNow = validFor
                     });
diff --git a/src/Microsoft.AspNetCore.ResponseCaching/ResponseCacheMiddleware.cs b/src/Microsoft.AspNetCore.ResponseCaching/ResponseCacheMiddleware.cs
index 6be81a9..000e031 100644
--- a/src/Microsoft.AspNetCore.ResponseCaching/ResponseCacheMiddleware.cs
+++ b/src/Microsoft.AspNetCore.ResponseCaching/ResponseCacheMiddleware.cs
@@ -111,8 +111,14 @@ namespace Microsoft.AspNetCore.ResponseCaching
             }
         }
 
-        internal async Task<bool> TryServeCachedResponseAsync(ResponseCacheContext context, CachedResponse cachedResponse)
+        internal async Task<bool> TryServeCachedResponseAsync(ResponseCacheContext context, IResponseCacheEntry cacheEntry)
         {
+            var cachedResponse = cacheEntry as CachedResponse;
+            if (cachedResponse == null)
+            {
+                return false;
+            }
+
             context.CachedResponse = cachedResponse;
             context.CachedResponseHeaders = new ResponseHeaders(cachedResponse.Headers);
             context.ResponseTime = _options.SystemClock.UtcNow;
@@ -171,24 +177,26 @@ namespace Microsoft.AspNetCore.ResponseCaching
             context.BaseKey = _keyProvider.CreateBaseKey(context);
             var cacheEntry = await _store.GetAsync(context.BaseKey);
 
-            if (cacheEntry is CachedVaryByRules)
+            var cachedVaryByRules = cacheEntry as CachedVaryByRules;
+            if (cachedVaryByRules != null)
             {
                 // Request contains vary rules, recompute key(s) and try again
-                context.CachedVaryByRules = (CachedVaryByRules)cacheEntry;
+                context.CachedVaryByRules = cachedVaryByRules;
 
                 foreach (var varyKey in _keyProvider.CreateLookupVaryByKeys(context))
                 {
-                    cacheEntry = await _store.GetAsync(varyKey);
-
-                    if (cacheEntry is CachedResponse && await TryServeCachedResponseAsync(context, (CachedResponse)cacheEntry))
+                    if (await TryServeCachedResponseAsync(context, await _store.GetAsync(varyKey)))
                     {
                         return true;
                     }
                 }
             }
-            else if (cacheEntry is CachedResponse && await TryServeCachedResponseAsync(context, (CachedResponse)cacheEntry))
+            else
             {
-                return true;
+                if (await TryServeCachedResponseAsync(context, cacheEntry))
+                {
+                    return true;
+                }
             }
 
             if (context.RequestCacheControlHeaderValue.OnlyIfCached)