diff --git a/services/hwfit/profiles.py b/services/hwfit/profiles.py
index 337af7648..5c885e38b 100644
--- a/services/hwfit/profiles.py
+++ b/services/hwfit/profiles.py
@@ -103,6 +103,9 @@ def compute_serve_profiles(system, model, serve_weights_gb=None, serve_quant=Non
     in the actual serving knobs (n_cpu_moe, KV-cache type, context). serve_quant
     is the file's quant label (e.g. "Q4_K_M") just for display.
     """
+    if not isinstance(system, dict) or not isinstance(model, dict):
+        return []
+
     vram = float(system.get("gpu_vram_gb") or 0)
     if vram <= 0:
         return []
diff --git a/tests/test_serve_profiles.py b/tests/test_serve_profiles.py
index e612a7a83..cc7e3788e 100644
--- a/tests/test_serve_profiles.py
+++ b/tests/test_serve_profiles.py
@@ -28,6 +28,12 @@ def _sys(vram, family="rdna"):
     return {"backend": "rocm", "gpu_vram_gb": vram, "gpu_family": family}
 
 
+def test_compute_serve_profiles_ignores_invalid_inputs():
+    assert compute_serve_profiles(None, _DENSE_8B) == []
+    assert compute_serve_profiles(_sys(8), None) == []
+    assert compute_serve_profiles(["bad"], _DENSE_8B) == []
+
+
 def test_big_moe_on_small_card_offloads_not_fails():
     """A 35B MoE can't hold its weights on 16 GB, so the Quality profile must
     offload experts to CPU (n_cpu_moe > 0) rather than be dropped."""