diff --git a/internal/translator/codex/gemini-cli/codex_gemini-cli_request_test.go b/internal/translator/codex/gemini-cli/codex_gemini-cli_request_test.go
new file mode 100644
index 000000000..fc41452b1
--- /dev/null
+++ b/internal/translator/codex/gemini-cli/codex_gemini-cli_request_test.go
@@ -0,0 +1,78 @@
+package geminiCLI
+
+import (
+	"testing"
+
+	"github.com/tidwall/gjson"
+)
+
+func TestConvertGeminiCLIRequestToCodex_PreservesSchemaPropertyNamedType(t *testing.T) {
+	input := []byte(`{
+		"request": {
+			"tools": [
+				{
+					"functionDeclarations": [
+						{
+							"name": "ask_user",
+							"description": "Ask the user one or more questions.",
+							"parametersJsonSchema": {
+								"type": "object",
+								"properties": {
+									"questions": {
+										"type": "array",
+										"items": {
+											"type": "object",
+											"properties": {
+												"header": {
+													"type": "string"
+												},
+												"type": {
+													"default": "choice",
+													"description": "Question type.",
+													"enum": [
+														"choice",
+														"text",
+														"yesno"
+													],
+													"type": "string"
+												}
+											},
+											"required": [
+												"question",
+												"header",
+												"type"
+											]
+										}
+									}
+								},
+								"required": [
+									"questions"
+								]
+							}
+						}
+					]
+				}
+			]
+		}
+	}`)
+
+	out := ConvertGeminiCLIRequestToCodex("gpt-5.2", input, true)
+	tool := gjson.GetBytes(out, "tools.0")
+	if got := tool.Get("type").String(); got != "function" {
+		t.Fatalf("expected tool type %q, got %q; output=%s", "function", got, string(out))
+	}
+
+	typeProperty := tool.Get("parameters.properties.questions.items.properties.type")
+	if !typeProperty.IsObject() {
+		t.Fatalf("expected schema property named type to stay an object; output=%s", string(out))
+	}
+	if got := typeProperty.Get("type").String(); got != "string" {
+		t.Fatalf("expected schema property type %q, got %q; output=%s", "string", got, string(out))
+	}
+	if got := typeProperty.Get("default").String(); got != "choice" {
+		t.Fatalf("expected default %q, got %q; output=%s", "choice", got, string(out))
+	}
+	if got := typeProperty.Get("enum.2").String(); got != "yesno" {
+		t.Fatalf("expected enum value %q, got %q; output=%s", "yesno", got, string(out))
+	}
+}
diff --git a/internal/translator/codex/gemini/codex_gemini_request.go b/internal/translator/codex/gemini/codex_gemini_request.go
index 23dae7d71..373997007 100644
--- a/internal/translator/codex/gemini/codex_gemini_request.go
+++ b/internal/translator/codex/gemini/codex_gemini_request.go
@@ -284,7 +284,11 @@ func ConvertGeminiRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 	util.Walk(toolsResult, "", "type", &pathsToLower)
 	for _, p := range pathsToLower {
 		fullPath := fmt.Sprintf("tools.%s", p)
-		out, _ = sjson.SetBytes(out, fullPath, strings.ToLower(gjson.GetBytes(out, fullPath).String()))
+		typeValue := gjson.GetBytes(out, fullPath)
+		if typeValue.Type != gjson.String {
+			continue
+		}
+		out, _ = sjson.SetBytes(out, fullPath, strings.ToLower(typeValue.String()))
 	}
 
 	return out