diff --git a/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go b/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go
index f18f45be..c8948ac5 100644
--- a/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go
+++ b/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go
@@ -147,21 +147,21 @@ func ConvertOpenAIRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 			content := m.Get("content")
 
 			if (role == "system" || role == "developer") && len(arr) > 1 {
-				// system -> system_instruction as a user message style
+				// system -> systemInstruction as a user message style
 				if content.Type == gjson.String {
-					out, _ = sjson.SetBytes(out, "system_instruction.role", "user")
-					out, _ = sjson.SetBytes(out, fmt.Sprintf("system_instruction.parts.%d.text", systemPartIndex), content.String())
+					out, _ = sjson.SetBytes(out, "systemInstruction.role", "user")
+					out, _ = sjson.SetBytes(out, fmt.Sprintf("systemInstruction.parts.%d.text", systemPartIndex), content.String())
 					systemPartIndex++
 				} else if content.IsObject() && content.Get("type").String() == "text" {
-					out, _ = sjson.SetBytes(out, "system_instruction.role", "user")
-					out, _ = sjson.SetBytes(out, fmt.Sprintf("system_instruction.parts.%d.text", systemPartIndex), content.Get("text").String())
+					out, _ = sjson.SetBytes(out, "systemInstruction.role", "user")
+					out, _ = sjson.SetBytes(out, fmt.Sprintf("systemInstruction.parts.%d.text", systemPartIndex), content.Get("text").String())
 					systemPartIndex++
 				} else if content.IsArray() {
 					contents := content.Array()
 					if len(contents) > 0 {
-						out, _ = sjson.SetBytes(out, "system_instruction.role", "user")
+						out, _ = sjson.SetBytes(out, "systemInstruction.role", "user")
 						for j := 0; j < len(contents); j++ {
-							out, _ = sjson.SetBytes(out, fmt.Sprintf("system_instruction.parts.%d.text", systemPartIndex), contents[j].Get("text").String())
+							out, _ = sjson.SetBytes(out, fmt.Sprintf("systemInstruction.parts.%d.text", systemPartIndex), contents[j].Get("text").String())
 							systemPartIndex++
 						}
 					}
diff --git a/internal/translator/gemini/openai/responses/gemini_openai-responses_request.go b/internal/translator/gemini/openai/responses/gemini_openai-responses_request.go
index 143359d6..463203a7 100644
--- a/internal/translator/gemini/openai/responses/gemini_openai-responses_request.go
+++ b/internal/translator/gemini/openai/responses/gemini_openai-responses_request.go
@@ -26,7 +26,7 @@ func ConvertOpenAIResponsesRequestToGemini(modelName string, inputRawJSON []byte
 	if instructions := root.Get("instructions"); instructions.Exists() {
 		systemInstr := `{"parts":[{"text":""}]}`
 		systemInstr, _ = sjson.Set(systemInstr, "parts.0.text", instructions.String())
-		out, _ = sjson.SetRaw(out, "system_instruction", systemInstr)
+		out, _ = sjson.SetRaw(out, "systemInstruction", systemInstr)
 	}
 
 	// Convert input messages to Gemini contents format
@@ -119,7 +119,7 @@ func ConvertOpenAIResponsesRequestToGemini(modelName string, inputRawJSON []byte
 				if strings.EqualFold(itemRole, "system") {
 					if contentArray := item.Get("content"); contentArray.Exists() {
 						systemInstr := ""
-						if systemInstructionResult := gjson.Get(out, "system_instruction"); systemInstructionResult.Exists() {
+						if systemInstructionResult := gjson.Get(out, "systemInstruction"); systemInstructionResult.Exists() {
 							systemInstr = systemInstructionResult.Raw
 						} else {
 							systemInstr = `{"parts":[]}`
@@ -140,7 +140,7 @@ func ConvertOpenAIResponsesRequestToGemini(modelName string, inputRawJSON []byte
 						}
 
 						if systemInstr != `{"parts":[]}` {
-							out, _ = sjson.SetRaw(out, "system_instruction", systemInstr)
+							out, _ = sjson.SetRaw(out, "systemInstruction", systemInstr)
 						}
 					}
 					continue