diff --git a/src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/HttpRequestAdapterFeature.cs b/src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/HttpRequestAdapterFeature.cs
index 9ee022e6fe..3ee4091c9c 100644
--- a/src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/HttpRequestAdapterFeature.cs
+++ b/src/Microsoft.AspNetCore.SystemWebAdapters.CoreServices/HttpRequestAdapterFeature.cs
@@ -160,7 +160,22 @@ Stream IHttpRequestFeature.Body
 
             return body;
         }
-        set => _other.Body = value;
+        set
+        {
+            _other.Body = value;
+            Reset();
+        }
+    }
+
+    private void Reset()
+    {
+        Mode = ReadEntityBodyMode.None;
+
+        if (_bufferedStream is not null)
+        {
+            _bufferedStream.Dispose();
+            _bufferedStream = null;
+        }
     }
 
     private Stream GetBody() => _bufferedStream ?? _other.Body;