diff --git a/ShareX.UploadersLib/FileUploaders/BackblazeB2.cs b/ShareX.UploadersLib/FileUploaders/BackblazeB2.cs
index fc6e3f78f..9dfc9100a 100644
--- a/ShareX.UploadersLib/FileUploaders/BackblazeB2.cs
+++ b/ShareX.UploadersLib/FileUploaders/BackblazeB2.cs
@@ -213,6 +213,12 @@ public override UploadResult Upload(Stream stream, string fileName)
                     DebugHelper.WriteLine("B2 uploader: Too Many Requests, trying with same URL.");
                     continue;
                 }
+                else if (uploadResult.RC == 503)
+                {
+                    DebugHelper.WriteLine("B2 uploader: Service Unavailable, trying with new URL.");
+                    url = null;
+                    continue;
+                }
                 else if (uploadResult.RC != 200)
                 {
                     // something else happened that wasn't a success, so bail out
@@ -678,4 +684,4 @@ public B2Upload(string fileId, string fileName, string accountId, string bucketI
 
         #endregion JSON responses
     }
-}
\ No newline at end of file
+}