@@ -58,8 +58,8 @@ public SimpleRetryHandler(Func<TimeSpan, Task> sleep)
         return null;
       }
       if (
-        int.TryParse(response.Headers.GetValueOrDefault("Retry-After"), out int secondsToWait)
-        || int.TryParse(response.Headers.GetValueOrDefault("retry-after"), out secondsToWait))
+        (response.Headers.ContainsKey("Retry-After") && int.TryParse(response.Headers["Retry-After"], out int secondsToWait))
+        || (response.Headers.ContainsKey("retry-after") && int.TryParse(response.Headers["retry-after"], out secondsToWait)))
       {
         return TimeSpan.FromSeconds(secondsToWait);
       }
Original file line number	Diff line number	Diff line change
`@@ -58,8 +58,8 @@ public SimpleRetryHandler(Func<TimeSpan, Task> sleep)`
`58`	`58`	`return null;`
`59`	`59`	`}`
`60`	`60`	`if (`
`61`		`- int.TryParse(response.Headers.GetValueOrDefault("Retry-After"), out int secondsToWait)`
`62`		`- \|\| int.TryParse(response.Headers.GetValueOrDefault("retry-after"), out secondsToWait))`
	`61`	`+ (response.Headers.ContainsKey("Retry-After") && int.TryParse(response.Headers["Retry-After"], out int secondsToWait))`
	`62`	`+ \|\| (response.Headers.ContainsKey("retry-after") && int.TryParse(response.Headers["retry-after"], out secondsToWait)))`
`63`	`63`	`{`
`64`	`64`	`return TimeSpan.FromSeconds(secondsToWait);`
`65`	`65`	`}`