diff --git a/packages/core/lib/v3/external_clients/aisdk.ts b/packages/core/lib/v3/external_clients/aisdk.ts
index 5a6eb41603..55de7b85fe 100644
--- a/packages/core/lib/v3/external_clients/aisdk.ts
+++ b/packages/core/lib/v3/external_clients/aisdk.ts
@@ -86,6 +86,7 @@ export class AISdkClient extends LLMClient {
         model: this.model,
         messages: formattedMessages,
         schema: options.response_model.schema,
+        allowSystemInMessages: true,
       });
 
       return {
@@ -113,6 +114,7 @@ export class AISdkClient extends LLMClient {
       model: this.model,
       messages: formattedMessages,
       tools,
+      allowSystemInMessages: true,
     });
 
     return {
diff --git a/packages/core/lib/v3/handlers/v3AgentHandler.ts b/packages/core/lib/v3/handlers/v3AgentHandler.ts
index cff08c8a28..773c3e67b7 100644
--- a/packages/core/lib/v3/handlers/v3AgentHandler.ts
+++ b/packages/core/lib/v3/handlers/v3AgentHandler.ts
@@ -374,7 +374,7 @@ export class V3AgentHandler {
         tools: allTools,
         stopWhen: (result) => this.handleStop(result, maxSteps),
         toolChoice: "auto",
-
+        allowSystemInMessages: true,
         prepareStep: this.createPrepareStep(
           callbacks?.prepareStep,
           captchaSolver,
@@ -511,6 +511,7 @@ export class V3AgentHandler {
         tools: allTools,
         stopWhen: (result) => this.handleStop(result, maxSteps),
         toolChoice: "auto",
+        allowSystemInMessages: true,
         prepareStep: this.createPrepareStep(
           callbacks?.prepareStep,
           captchaSolver,
diff --git a/packages/core/lib/v3/llm/aisdk.ts b/packages/core/lib/v3/llm/aisdk.ts
index 355b46d425..81bb924dcf 100644
--- a/packages/core/lib/v3/llm/aisdk.ts
+++ b/packages/core/lib/v3/llm/aisdk.ts
@@ -248,6 +248,7 @@ You must respond in JSON format. respond WITH JSON. Do not include any other tex
           messages: formattedMessages,
           schema: options.response_model.schema,
           temperature,
+          allowSystemInMessages: true,
           ...(Object.keys(providerOptions).length > 0
             ? { providerOptions }
             : {}),
@@ -379,6 +380,7 @@ You must respond in JSON format. respond WITH JSON. Do not include any other tex
                 : "auto"
             : undefined,
         temperature,
+        allowSystemInMessages: true,
       });
     } catch (err) {
       // Log error response to maintain request/response pairing
diff --git a/packages/evals/lib/AISdkClientWrapped.ts b/packages/evals/lib/AISdkClientWrapped.ts
index 213aaa0f34..934a686e03 100644
--- a/packages/evals/lib/AISdkClientWrapped.ts
+++ b/packages/evals/lib/AISdkClientWrapped.ts
@@ -180,6 +180,7 @@ You must respond in JSON format. respond WITH JSON. Do not include any other tex
           messages: formattedMessages,
           schema: options.response_model.schema,
           temperature,
+          allowSystemInMessages: true,
           providerOptions: resolvedReasoningEffort
             ? {
                 openai: {
@@ -289,6 +290,7 @@ You must respond in JSON format. respond WITH JSON. Do not include any other tex
                 : "auto"
             : undefined,
         temperature,
+        allowSystemInMessages: true,
       });
 
     // Transform AI SDK response to match LLMResponse format expected by operator handler.