diff --git a/packages/plugins/plugin-workspace-diff/src/diff-model.ts b/packages/plugins/plugin-workspace-diff/src/diff-model.ts
index 4ceeba34272..ca500e6633d 100644
--- a/packages/plugins/plugin-workspace-diff/src/diff-model.ts
+++ b/packages/plugins/plugin-workspace-diff/src/diff-model.ts
@@ -92,7 +92,6 @@ export function isLongDiffFile(file: Pick<DiffFileViewModel, "lineCount">) {
 
 export function toFileViewModels(diff: WorkspaceDiffResponse | null | undefined): DiffFileViewModel[] {
   return (diff?.files ?? []).map((file) => {
-    const patchWarnings = file.patches.flatMap((patch) => patch.warnings);
     const patches = buildFilePatches(file);
     const lineCount = patches.reduce((count, patch) => count + patch.lineCount, 0);
     return {
@@ -104,7 +103,7 @@ export function toFileViewModels(diff: WorkspaceDiffResponse | null | undefined)
       binary: file.binary,
       oversized: file.oversized,
       truncated: file.truncated,
-      warnings: [...file.warnings, ...patchWarnings],
+      warnings: file.warnings,
       patchKinds: file.patches.map((patch) => patch.kind),
       patches,
       patch: patches.find((patch) => patch.patch)?.patch ?? null,
@@ -119,10 +118,7 @@ export function diffSummary(diff: WorkspaceDiffResponse | null | undefined): Dif
   const fileCount = stats?.fileCount ?? 0;
   const additions = stats?.additions ?? 0;
   const deletions = stats?.deletions ?? 0;
-  const warningCount = (diff?.warnings.length ?? 0)
-    + (diff?.files ?? []).reduce((count, file) => {
-      return count + file.warnings.length + file.patches.reduce((patchCount, patch) => patchCount + patch.warnings.length, 0);
-    }, 0);
+  const warningCount = diff?.warnings.length ?? 0;
 
   return {
     changedLabel: `${fileCount} ${fileCount === 1 ? "file" : "files"}`,
diff --git a/packages/plugins/plugin-workspace-diff/tests/diff-model.spec.ts b/packages/plugins/plugin-workspace-diff/tests/diff-model.spec.ts
index dde2656eb86..8ab427c5583 100644
--- a/packages/plugins/plugin-workspace-diff/tests/diff-model.spec.ts
+++ b/packages/plugins/plugin-workspace-diff/tests/diff-model.spec.ts
@@ -38,20 +38,45 @@ describe("workspace diff UI model", () => {
   });
 
   it("surfaces truncation and file warnings", () => {
+    const warning = { code: "patch_truncated" as const, message: "Patch was truncated.", path: "src/app.ts" };
     const file = changedFile({
       truncated: true,
-      warnings: [{ code: "patch_truncated", message: "Patch was truncated.", path: "src/app.ts" }],
+      warnings: [warning],
       patches: [],
     });
-    const diff = diffResponse({ files: [file], truncated: true });
+    const diff = diffResponse({ files: [file], truncated: true, warnings: [warning] });
 
     expect(buildFilePatch(file)).toBeNull();
+    expect(toFileViewModels(diff)[0]?.warnings).toEqual([warning]);
     expect(diffSummary(diff)).toMatchObject({
       warningCount: 1,
       truncated: true,
     });
   });
 
+  it("does not duplicate aggregated patch warnings", () => {
+    const warning = { code: "patch_truncated" as const, message: "Patch was truncated.", path: "src/app.ts" };
+    const file = changedFile({
+      warnings: [warning],
+      patches: [
+        {
+          kind: "unstaged",
+          patch: null,
+          additions: 0,
+          deletions: 0,
+          binary: false,
+          oversized: false,
+          truncated: true,
+          warnings: [warning],
+        },
+      ],
+    });
+    const diff = diffResponse({ files: [file], warnings: [warning] });
+
+    expect(toFileViewModels(diff)[0]?.warnings).toEqual([warning]);
+    expect(diffSummary(diff).warningCount).toBe(1);
+  });
+
   it("keeps staged and unstaged patches renderable as separate single-file diffs", () => {
     const stagedPatch = [
       "diff --git a/src/app.ts b/src/app.ts",