diff --git a/tools/test-proxy/Azure.Sdk.Tools.TestProxy/RecordingHandler.cs b/tools/test-proxy/Azure.Sdk.Tools.TestProxy/RecordingHandler.cs
index 5e033feaa7a..08511273dd8 100644
--- a/tools/test-proxy/Azure.Sdk.Tools.TestProxy/RecordingHandler.cs
+++ b/tools/test-proxy/Azure.Sdk.Tools.TestProxy/RecordingHandler.cs
@@ -457,16 +457,19 @@ public async Task HandlePlaybackRequest(string recordingId, HttpRequest incoming
 
             var sanitizers = SanitizerRegistry.GetSanitizers(session);
 
-            // we don't need to re-sanitize with recording-applicable sanitizers every time. just the very first one
-            lock (session)
+            if (!session.IsSanitized)
             {
-                if (!session.IsSanitized)
+                // we don't need to re-sanitize with recording-applicable sanitizers every time. just the very first one
+                lock (session)
                 {
-                    session.IsSanitized = true;
-
-                    foreach (RecordedTestSanitizer sanitizer in sanitizers)
+                    if (!session.IsSanitized)
                     {
-                        session.Session.Sanitize(sanitizer);
+                        foreach (RecordedTestSanitizer sanitizer in sanitizers)
+                        {
+                            session.Session.Sanitize(sanitizer);
+                        }
+
+                        session.IsSanitized = true;
                     }
                 }
             }