diff --git a/SpotifyAPI.Web/Models/Request/RequestParams.cs b/SpotifyAPI.Web/Models/Request/RequestParams.cs
index 4a34c85e..d12622ed 100644
--- a/SpotifyAPI.Web/Models/Request/RequestParams.cs
+++ b/SpotifyAPI.Web/Models/Request/RequestParams.cs
@@ -21,9 +21,9 @@ namespace SpotifyAPI.Web
       var body = new JObject();
       var type = GetType();
 
-      if (!_bodyParamsCache.IsEmpty && _bodyParamsCache.ContainsKey(type))
+      if (!_bodyParamsCache.IsEmpty && _bodyParamsCache.TryGetValue(type, out var bodyParamsCached))
       {
-        foreach (var (info, attribute) in _bodyParamsCache[type])
+        foreach (var (info, attribute) in bodyParamsCached)
         {
           AddBodyParam(body, info, attribute);
         }
@@ -70,9 +70,9 @@ namespace SpotifyAPI.Web
       var queryParams = new Dictionary<string, string>();
       var type = GetType();
 
-      if (!_queryParamsCache.IsEmpty && _queryParamsCache.ContainsKey(type))
+      if (!_queryParamsCache.IsEmpty && _queryParamsCache.TryGetValue(type, out var queryParamsCached))
       {
-        foreach (var (info, attribute) in _queryParamsCache[type])
+        foreach (var (info, attribute) in queryParamsCached)
         {
           AddQueryParam(queryParams, info, attribute);
         }
diff --git a/SpotifyAPI.Web/Util/PKCEUtil.cs b/SpotifyAPI.Web/Util/PKCEUtil.cs
index 02eec991..8611ce2c 100644
--- a/SpotifyAPI.Web/Util/PKCEUtil.cs
+++ b/SpotifyAPI.Web/Util/PKCEUtil.cs
@@ -63,8 +63,12 @@ namespace SpotifyAPI.Web
 
     private static byte[] ComputeSHA256(string value)
     {
+#if NETSTANDARD2_1_OR_GREATER
       using var hash = SHA256.Create();
       return hash.ComputeHash(Encoding.UTF8.GetBytes(value));
+#else
+      return SHA256.HashData(Encoding.UTF8.GetBytes(value));
+#endif
     }
   }
 }