diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index 0f8cbd23f775..70c58b347a26 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -1579,6 +1579,8 @@ const layer = Layer.effect(
         for (const [id, provider] of Object.entries(database)) {
           const providerID = ProviderV2.ID.make(id)
           if (disabled.has(providerID)) continue
+          // GITHUB_TOKEN is commonly set for GitHub tooling; github-copilot must only activate through its OAuth plugin flow.
+          if (providerID === ProviderV2.ID.githubCopilot) continue
           const apiKey = provider.env.map((item) => envs[item]).find(Boolean)
           if (!apiKey) continue
           mergeProvider(providerID, {
diff --git a/packages/opencode/test/provider/provider.test.ts b/packages/opencode/test/provider/provider.test.ts
index 32d4e3a39b10..88bb3de0b210 100644
--- a/packages/opencode/test/provider/provider.test.ts
+++ b/packages/opencode/test/provider/provider.test.ts
@@ -121,6 +121,14 @@ it.instance("provider loaded from env variable", () =>
   }),
 )
 
+it.instance("GITHUB_TOKEN does not activate github-copilot", () =>
+  Effect.gen(function* () {
+    yield* setProcessEnv("GITHUB_TOKEN", "test-github-token")
+    const providers = yield* list
+    expect(providers[ProviderV2.ID.githubCopilot]).toBeUndefined()
+  }),
+)
+
 it.instance(
   "provider loaded from config with apiKey option",
   Effect.gen(function* () {