diff --git a/src/agents/model-ref-shared.test.ts b/src/agents/model-ref-shared.test.ts
new file mode 100644
index 00000000000..d54efae8818
--- /dev/null
+++ b/src/agents/model-ref-shared.test.ts
@@ -0,0 +1,16 @@
+import { describe, expect, it } from "vitest";
+import { normalizeStaticProviderModelId } from "./model-ref-shared.js";
+
+describe("normalizeStaticProviderModelId", () => {
+  it("re-adds the nvidia prefix for bare model ids", () => {
+    expect(normalizeStaticProviderModelId("nvidia", "nemotron-3-super-120b-a12b")).toBe(
+      "nvidia/nemotron-3-super-120b-a12b",
+    );
+  });
+
+  it("does not double-prefix already prefixed models", () => {
+    expect(normalizeStaticProviderModelId("nvidia", "nvidia/nemotron-3-super-120b-a12b")).toBe(
+      "nvidia/nemotron-3-super-120b-a12b",
+    );
+  });
+});
diff --git a/src/agents/model-ref-shared.ts b/src/agents/model-ref-shared.ts
index 09d1a7466d7..5b9a3357b84 100644
--- a/src/agents/model-ref-shared.ts
+++ b/src/agents/model-ref-shared.ts
@@ -69,6 +69,9 @@ export function normalizeStaticProviderModelId(provider: string, model: string):
   if (provider === "openrouter" && !model.includes("/")) {
     return `openrouter/${model}`;
   }
+  if (provider === "nvidia" && !model.includes("/")) {
+    return `nvidia/${model}`;
+  }
   if (provider === "xai") {
     return normalizeNativeXaiModelId(model);
   }