diff --git a/backend/routers/prompts.py b/backend/routers/prompts.py
index 1f32011..cc438db 100644
--- a/backend/routers/prompts.py
+++ b/backend/routers/prompts.py
@@ -1488,6 +1488,14 @@ async def execute_unified_prompt(
             'vitalwerte': 7
         }
 
+    # Wrapper function to match workflow_executor's expected signature: (prompt, model) -> str
+    # workflow_executor calls: openrouter_call_func(prompt, "anthropic/claude-sonnet-4")
+    # but call_openrouter expects: call_openrouter(prompt, max_tokens=4096)
+    async def workflow_llm_call(prompt: str, model: str = None) -> str:
+        # Ignore model parameter (already set in OPENROUTER_MODEL env var)
+        # Use default max_tokens=4096 from call_openrouter
+        return await call_openrouter(prompt)
+
     # Execute with prompt_executor
     # Always enable debug when saving to collect metadata for value table
     result = await execute_prompt_with_data(
@@ -1495,7 +1503,7 @@ async def execute_unified_prompt(
         profile_id=profile_id,
         modules=modules,
         timeframes=timeframes,
-        openrouter_call_func=call_openrouter,
+        openrouter_call_func=workflow_llm_call,  # Use wrapper with correct signature
         enable_debug=debug or save  # Enable debug if saving for metadata collection
     )