diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index 8c1d24f4f1..74b004a458 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -1981,36 +1981,14 @@ async fn run_turn(
         .get_model_family()
         .supports_parallel_tool_calls;
     let parallel_tool_calls = model_supports_parallel;
-    let mut allowed_tools = Vec::new();
-    let mut restricted_tool_choice = false;
-    for tool in router.allowed_tools() {
-        let is_disabled = tool
-            .get("name")
-            .and_then(|val| val.as_str())
-            .is_some_and(|name| {
-                turn_context
-                    .disabled_tools
-                    .iter()
-                    .any(|disabled| disabled.matches_tool_name(name))
-            });
-        if is_disabled {
-            restricted_tool_choice = true;
-            continue;
-        }
-        allowed_tools.push(tool);
-    }
-    let allowed_tools = if restricted_tool_choice {
-        Some(allowed_tools)
-    } else {
-        None
-    };
+    let allowed_tools = router.allowed_tools(turn_context.disabled_tools.clone());
     let prompt = Prompt {
         input,
         tools: router.specs(),
         parallel_tool_calls,
         base_instructions_override: turn_context.base_instructions.clone(),
         output_schema: turn_context.final_output_json_schema.clone(),
-        allowed_tools,
+        allowed_tools: Some(allowed_tools),
     };
 
     let mut retries = 0;
diff --git a/codex-rs/core/src/tools/router.rs b/codex-rs/core/src/tools/router.rs
index 24e93e2192..2367a02d98 100644
--- a/codex-rs/core/src/tools/router.rs
+++ b/codex-rs/core/src/tools/router.rs
@@ -16,6 +16,7 @@ use codex_protocol::models::LocalShellAction;
 use codex_protocol::models::ResponseInputItem;
 use codex_protocol::models::ResponseItem;
 use codex_protocol::models::ShellToolCallParams;
+use codex_protocol::protocol::DisabledTool;
 use serde_json::json;
 
 #[derive(Clone)]
@@ -48,12 +49,18 @@ impl ToolRouter {
             .collect()
     }
 
-    pub fn allowed_tools(&self) -> Vec<serde_json::Value> {
+    pub fn allowed_tools(&self, disabled_tools: Vec<DisabledTool>) -> Vec<serde_json::Value> {
         self.specs
             .iter()
-            .map(|config| {
+            .filter_map(|config| {
                 let name = config.spec.name();
-                json!({"type": "function", "name": name})
+                if disabled_tools
+                    .iter()
+                    .any(|disabled| disabled.matches_tool_name(name))
+                {
+                    return None;
+                }
+                Some(json!({"type": "function", "name": name}))
             })
             .collect()
     }