diff --git a/nanobot/config/schema.py b/nanobot/config/schema.py
index 2012d3df1..521c583dc 100644
--- a/nanobot/config/schema.py
+++ b/nanobot/config/schema.py
@@ -504,6 +504,7 @@ class Config(BaseSettings):
         model_normalized = model_lower.replace("-", "_")
         model_prefix = model_lower.split("/", 1)[0] if "/" in model_lower else ""
         normalized_prefix = model_prefix.replace("-", "_")
+        prefixed_provider = find_by_name(model_prefix) if model_prefix else None
 
         def _kw_matches(kw: str) -> bool:
             kw = kw.lower()
@@ -540,8 +541,15 @@ class Config(BaseSettings):
                 # honor a local keyword match when the user has actually
                 # configured that local endpoint via `api_base` — mirrors the
                 # gate already used by the local-fallback loop below.
-                if spec.is_local and not p.api_base:
-                    continue
+                if spec.is_local:
+                    # A qualified model belongs to its explicit provider or a
+                    # gateway fallback, never to a different local provider
+                    # whose model-family keyword happens to match.
+                    foreign_prefix = bool(
+                        prefixed_provider is not None and prefixed_provider.name != spec.name
+                    )
+                    if not p.api_base or foreign_prefix:
+                        continue
                 if spec.is_oauth or spec.is_local or spec.is_direct or p.api_key:
                     return p, spec.name
 
@@ -550,16 +558,17 @@ class Config(BaseSettings):
         # Prefer providers whose detect_by_base_keyword matches the configured api_base
         # (e.g. Ollama's "11434" in "http://localhost:11434") over plain registry order.
         local_fallback: tuple[ProviderConfig, str] | None = None
-        for spec in PROVIDERS:
-            if not spec.is_local:
-                continue
-            p = getattr(self.providers, spec.name, None)
-            if not (p and p.api_base):
-                continue
-            if spec.detect_by_base_keyword and spec.detect_by_base_keyword in p.api_base:
-                return p, spec.name
-            if local_fallback is None:
-                local_fallback = (p, spec.name)
+        if prefixed_provider is None:
+            for spec in PROVIDERS:
+                if not spec.is_local:
+                    continue
+                p = getattr(self.providers, spec.name, None)
+                if not (p and p.api_base):
+                    continue
+                if spec.detect_by_base_keyword and spec.detect_by_base_keyword in p.api_base:
+                    return p, spec.name
+                if local_fallback is None:
+                    local_fallback = (p, spec.name)
         if local_fallback:
             return local_fallback
 
diff --git a/tests/cli/test_commands.py b/tests/cli/test_commands.py
index 647dbb166..bc4bc6a70 100644
--- a/tests/cli/test_commands.py
+++ b/tests/cli/test_commands.py
@@ -1196,6 +1196,27 @@ def test_config_bare_nemotron_still_auto_routes_to_configured_ollama():
     assert config.get_api_base() == "http://localhost:11434/v1"
 
 
+def test_config_cloud_nemotron_is_not_hijacked_by_configured_ollama():
+    """An explicit cloud namespace takes precedence over local keywords."""
+    config = Config.model_validate(
+        {
+            "agents": {
+                "defaults": {
+                    "provider": "auto",
+                    "model": "nvidia/nemotron-3-super-120b-a12b",
+                }
+            },
+            "providers": {
+                "ollama": {"apiBase": "http://localhost:11434/v1"},
+                "openrouter": {"apiKey": "sk-or-test"},
+            },
+        }
+    )
+
+    assert config.get_provider_name() == "openrouter"
+    assert config.get_api_base() == "https://openrouter.ai/api/v1"
+
+
 def test_openai_compat_provider_passes_model_through():
     from nanobot.providers.openai_compat_provider import OpenAICompatProvider