diff --git a/internal/thinking/provider/interactions/apply.go b/internal/thinking/provider/interactions/apply.go
index c644f5add..b23f0d74e 100644
--- a/internal/thinking/provider/interactions/apply.go
+++ b/internal/thinking/provider/interactions/apply.go
@@ -77,7 +77,10 @@ func applyInteractionsNone(result, original []byte, config thinking.ThinkingConf
 	if config.Budget > 0 {
 		return applyInteractionsBudget(result, original, config.Budget, modelInfo)
 	}
-	return setInteractionsThinkingSummaries(result, original)
+	// With the amount fully disabled, visibility is irrelevant. Restoring
+	// thinking_summaries alone could make a default-on model reason and return a
+	// summary despite the explicit none override.
+	return result
 }
 
 func stripInteractionsThinkingFields(body []byte) []byte {
diff --git a/test/summary_intent_translation_test.go b/test/summary_intent_translation_test.go
index cc1724f5b..b19f01296 100644
--- a/test/summary_intent_translation_test.go
+++ b/test/summary_intent_translation_test.go
@@ -144,6 +144,7 @@ func TestSummaryIntentFinalPipeline(t *testing.T) {
 		{name: "Summary-only control is stripped for non-thinking Gemini model", from: sdktranslator.FormatOpenAIResponse, to: sdktranslator.FormatGemini, model: "no-thinking-model", body: `{"model":"no-thinking-model","reasoning":{"summary":"auto"},"input":"hi"}`, path: "generationConfig.thinkingConfig"},
 		{name: "Interactions level alone keeps summaries omitted", from: sdktranslator.FormatInteractions, to: sdktranslator.FormatInteractions, model: "level-model", body: `{"model":"level-model","generation_config":{"thinking_level":"high"},"input":"hi"}`, path: "generation_config.thinking_summaries"},
 		{name: "Interactions auto survives its applier", from: sdktranslator.FormatInteractions, to: sdktranslator.FormatInteractions, model: "level-model", body: `{"model":"level-model","generation_config":{"thinking_level":"high","thinking_summaries":"auto"},"input":"hi"}`, path: "generation_config.thinking_summaries", want: "auto", wantExists: true},
+		{name: "Interactions suffix none removes summary visibility", from: sdktranslator.FormatInteractions, to: sdktranslator.FormatInteractions, model: "gemini-toggle-mixed-model(none)", body: `{"model":"gemini-toggle-mixed-model(none)","generation_config":{"thinking_summaries":"auto"},"input":"hi"}`, path: "generation_config.thinking_summaries"},
 		{name: "Interactions reasoning effort leaves Antigravity summaries unspecified", from: sdktranslator.FormatInteractions, to: sdktranslator.FormatAntigravity, model: "antigravity-budget-model", body: `{"model":"antigravity-budget-model","reasoning":{"effort":"high"},"input":"hi"}`, path: "request.generationConfig.thinkingConfig.includeThoughts"},
 		{name: "Interactions reasoning summary auto reaches Antigravity", from: sdktranslator.FormatInteractions, to: sdktranslator.FormatAntigravity, model: "antigravity-budget-model", body: `{"model":"antigravity-budget-model","reasoning":{"effort":"high","summary":"auto"},"input":"hi"}`, path: "request.generationConfig.thinkingConfig.includeThoughts", want: "true", wantExists: true},
 		{name: "Interactions reasoning summary none reaches Antigravity", from: sdktranslator.FormatInteractions, to: sdktranslator.FormatAntigravity, model: "antigravity-budget-model", body: `{"model":"antigravity-budget-model","reasoning":{"effort":"high","summary":"none"},"input":"hi"}`, path: "request.generationConfig.thinkingConfig.includeThoughts", want: "false", wantExists: true},