diff --git a/src/agents/tools/image-generate-tool.test.ts b/src/agents/tools/image-generate-tool.test.ts
index 359febc6118..e811ecd4c4a 100644
--- a/src/agents/tools/image-generate-tool.test.ts
+++ b/src/agents/tools/image-generate-tool.test.ts
@@ -180,6 +180,44 @@ describe("createImageGenerateTool", () => {
     expect(createImageGenerateTool({ config: {} })).toBeNull();
   });
 
+  it("matches image-generation providers across canonical provider aliases", () => {
+    vi.spyOn(imageGenerationRuntime, "listRuntimeImageGenerationProviders").mockReturnValue([
+      {
+        id: "z.ai",
+        aliases: ["z-ai"],
+        defaultModel: "glm-4.5-image",
+        models: ["glm-4.5-image"],
+        capabilities: {
+          generate: {
+            maxCount: 4,
+          },
+          edit: {
+            enabled: false,
+            maxInputImages: 0,
+          },
+          geometry: {},
+        },
+        generateImage: vi.fn(async () => {
+          throw new Error("not used");
+        }),
+      },
+    ]);
+
+    expect(
+      createImageGenerateTool({
+        config: {
+          agents: {
+            defaults: {
+              imageGenerationModel: {
+                primary: "z-ai/glm-4.5-image",
+              },
+            },
+          },
+        },
+      }),
+    ).not.toBeNull();
+  });
+
   it("infers an OpenAI image-generation model from env-backed auth", () => {
     stubImageGenerationProviders();
     vi.stubEnv("OPENAI_API_KEY", "openai-test");
diff --git a/src/agents/tools/image-generate-tool.ts b/src/agents/tools/image-generate-tool.ts
index 9a0619ffca9..5056c1bb1d4 100644
--- a/src/agents/tools/image-generate-tool.ts
+++ b/src/agents/tools/image-generate-tool.ts
@@ -16,6 +16,7 @@ import { saveMediaBuffer } from "../../media/store.js";
 import { loadWebMedia } from "../../media/web-media.js";
 import { getProviderEnvVars } from "../../secrets/provider-env-vars.js";
 import { resolveUserPath } from "../../utils.js";
+import { normalizeProviderId } from "../provider-id.js";
 import { ToolInputError, readNumberParam, readStringParam } from "./common.js";
 import { decodeDataUrl } from "./image-tool.helpers.js";
 import {
@@ -247,10 +248,11 @@ function resolveSelectedImageGenerationProvider(params: {
   if (!selectedRef) {
     return undefined;
   }
+  const selectedProvider = normalizeProviderId(selectedRef.provider);
   return listRuntimeImageGenerationProviders({ config: params.config }).find(
     (provider) =>
-      provider.id === selectedRef.provider ||
-      (provider.aliases ?? []).includes(selectedRef.provider),
+      normalizeProviderId(provider.id) === selectedProvider ||
+      (provider.aliases ?? []).some((alias) => normalizeProviderId(alias) === selectedProvider),
   );
 }