diff --git a/providers/openrouter/language_model_hooks.go b/providers/openrouter/language_model_hooks.go
index 4ed73c446558eb19c157d3e3d9246a0026d9ff48..c2f3d812f320b04488b643b5bbd7b2615f37f20e 100644
--- a/providers/openrouter/language_model_hooks.go
+++ b/providers/openrouter/language_model_hooks.go
@@ -295,8 +295,7 @@ func languageModelStreamExtra(chunk openaisdk.ChatCompletionChunk, yield func(fa
 		currentState.format = detail.Format
 		ctx[reasoningStartedCtx] = currentState
 		delta := detail.Summary
-		if strings.HasPrefix(detail.Format, "google-gemini") ||
-			strings.HasPrefix(detail.Format, "anthropic-claude") {
+		if xstrings.ContainsAnyOf(detail.Format, "google-gemini", "anthropic-claude") {
 			delta = detail.Text
 		}
 		return ctx, yield(fantasy.StreamPart{