diff --git a/toolkit/components/mediasniffer/nsMediaSniffer.cpp b/toolkit/components/mediasniffer/nsMediaSniffer.cpp
index 5e1e09a6cfaf..679b2287ffac 100644
--- a/toolkit/components/mediasniffer/nsMediaSniffer.cpp
+++ b/toolkit/components/mediasniffer/nsMediaSniffer.cpp
@@ -75,16 +75,15 @@ nsMediaSniffer::GetMIMETypeFromContent(nsIRequest* aRequest,
   // For media, we want to sniff only if the Content-Type is unknown, or if it
   // is application/octet-stream.
   nsCOMPtr<nsIChannel> channel = do_QueryInterface(aRequest);
-  if (!channel) {
-    return NS_ERROR_NOT_AVAILABLE;
-  }
-  nsAutoCString contentType;
-  nsresult rv = channel->GetContentType(contentType);
-  NS_ENSURE_SUCCESS(rv, rv);
-  if (!contentType.IsEmpty() &&
-      !contentType.EqualsLiteral(APPLICATION_OCTET_STREAM) &&
-      !contentType.EqualsLiteral(UNKNOWN_CONTENT_TYPE)) {
-    return NS_ERROR_NOT_AVAILABLE;
+  if (channel) {
+    nsAutoCString contentType;
+    nsresult rv = channel->GetContentType(contentType);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (!contentType.IsEmpty() &&
+        !contentType.EqualsLiteral(APPLICATION_OCTET_STREAM) &&
+        !contentType.EqualsLiteral(UNKNOWN_CONTENT_TYPE)) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
   }
 
   const uint32_t clampedLength = NS_MIN(aLength, MAX_BYTES_SNIFFED);