diff --git a/.changeset/tasty-hotels-press.md b/.changeset/tasty-hotels-press.md
new file mode 100644
index 00000000000..c79a5db61d6
--- /dev/null
+++ b/.changeset/tasty-hotels-press.md
@@ -0,0 +1,5 @@
+---
+"@apollo/client": patch
+---
+
+Fix issue where setting a default `watchQuery` option in the `ApolloClient` constructor could break `startTransition` when used with suspense hooks.
diff --git a/.size-limits.json b/.size-limits.json
index 2c7dbd56314..10e91f0ebf7 100644
--- a/.size-limits.json
+++ b/.size-limits.json
@@ -1,4 +1,4 @@
 {
-  "dist/apollo-client.min.cjs": 39273,
+  "dist/apollo-client.min.cjs": 39277,
   "import { ApolloClient, InMemoryCache, HttpLink } from \"dist/index.js\" (production)": 32630
 }
diff --git a/src/react/hooks/__tests__/useBackgroundQuery.test.tsx b/src/react/hooks/__tests__/useBackgroundQuery.test.tsx
index adcc9f430d2..045f7221e7a 100644
--- a/src/react/hooks/__tests__/useBackgroundQuery.test.tsx
+++ b/src/react/hooks/__tests__/useBackgroundQuery.test.tsx
@@ -5249,6 +5249,210 @@ describe("fetchMore", () => {
 
     await expect(Profiler).not.toRerender();
   });
+
+  // https://github.com/apollographql/apollo-client/issues/11708
+  it("`fetchMore` works with startTransition when setting errorPolicy as default option in ApolloClient constructor", async () => {
+    type Variables = {
+      offset: number;
+    };
+
+    interface Todo {
+      __typename: "Todo";
+      id: string;
+      name: string;
+      completed: boolean;
+    }
+    interface Data {
+      todos: Todo[];
+    }
+    const user = userEvent.setup();
+
+    const query: TypedDocumentNode<Data, Variables> = gql`
+      query TodosQuery($offset: Int!) {
+        todos(offset: $offset) {
+          id
+          name
+          completed
+        }
+      }
+    `;
+
+    const mocks: MockedResponse<Data, Variables>[] = [
+      {
+        request: { query, variables: { offset: 0 } },
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "1",
+                name: "Clean room",
+                completed: false,
+              },
+            ],
+          },
+        },
+        delay: 10,
+      },
+      {
+        request: { query, variables: { offset: 1 } },
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "2",
+                name: "Take out trash",
+                completed: true,
+              },
+            ],
+          },
+        },
+        delay: 10,
+      },
+    ];
+
+    const Profiler = createProfiler({
+      initialSnapshot: {
+        isPending: false,
+        result: null as UseReadQueryResult<Data> | null,
+      },
+    });
+
+    const { SuspenseFallback, ReadQueryHook } =
+      createDefaultTrackedComponents(Profiler);
+
+    const client = new ApolloClient({
+      link: new MockLink(mocks),
+      cache: new InMemoryCache({
+        typePolicies: {
+          Query: {
+            fields: {
+              todos: offsetLimitPagination(),
+            },
+          },
+        },
+      }),
+      defaultOptions: {
+        watchQuery: {
+          errorPolicy: "all",
+        },
+      },
+    });
+
+    function App() {
+      useTrackRenders();
+      const [isPending, startTransition] = React.useTransition();
+      const [queryRef, { fetchMore }] = useBackgroundQuery(query, {
+        variables: { offset: 0 },
+      });
+
+      Profiler.mergeSnapshot({ isPending });
+
+      return (
+        <>
+          <button
+            onClick={() => {
+              startTransition(() => {
+                fetchMore({ variables: { offset: 1 } });
+              });
+            }}
+          >
+            Load more
+          </button>
+          <Suspense fallback={<SuspenseFallback />}>
+            <ReadQueryHook queryRef={queryRef} />
+          </Suspense>
+        </>
+      );
+    }
+
+    renderWithClient(<App />, { client, wrapper: Profiler });
+
+    {
+      const { renderedComponents } = await Profiler.takeRender();
+
+      expect(renderedComponents).toStrictEqual([App, SuspenseFallback]);
+    }
+
+    {
+      const { snapshot } = await Profiler.takeRender();
+
+      expect(snapshot).toEqual({
+        isPending: false,
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "1",
+                name: "Clean room",
+                completed: false,
+              },
+            ],
+          },
+          error: undefined,
+          networkStatus: NetworkStatus.ready,
+        },
+      });
+    }
+
+    await act(() => user.click(screen.getByText("Load more")));
+
+    {
+      const { snapshot, renderedComponents } = await Profiler.takeRender();
+
+      expect(renderedComponents).toStrictEqual([App, ReadQueryHook]);
+      expect(snapshot).toEqual({
+        isPending: true,
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "1",
+                name: "Clean room",
+                completed: false,
+              },
+            ],
+          },
+          error: undefined,
+          networkStatus: NetworkStatus.ready,
+        },
+      });
+    }
+
+    {
+      const { snapshot, renderedComponents } = await Profiler.takeRender();
+
+      expect(renderedComponents).toStrictEqual([App, ReadQueryHook]);
+      expect(snapshot).toEqual({
+        isPending: false,
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "1",
+                name: "Clean room",
+                completed: false,
+              },
+              {
+                __typename: "Todo",
+                id: "2",
+                name: "Take out trash",
+                completed: true,
+              },
+            ],
+          },
+          error: undefined,
+          networkStatus: NetworkStatus.ready,
+        },
+      });
+    }
+
+    await expect(Profiler).not.toRerender();
+  });
 });
 
 describe.skip("type tests", () => {
diff --git a/src/react/hooks/__tests__/useSuspenseQuery.test.tsx b/src/react/hooks/__tests__/useSuspenseQuery.test.tsx
index 9a0e61fd55f..9fbbc524521 100644
--- a/src/react/hooks/__tests__/useSuspenseQuery.test.tsx
+++ b/src/react/hooks/__tests__/useSuspenseQuery.test.tsx
@@ -10109,6 +10109,225 @@ describe("useSuspenseQuery", () => {
     await expect(Profiler).not.toRerender();
   });
 
+  // https://github.com/apollographql/apollo-client/issues/11708
+  it("`fetchMore` works with startTransition when setting errorPolicy as default option in ApolloClient constructor", async () => {
+    type Variables = {
+      offset: number;
+    };
+
+    interface Todo {
+      __typename: "Todo";
+      id: string;
+      name: string;
+      completed: boolean;
+    }
+    interface Data {
+      todos: Todo[];
+    }
+    const user = userEvent.setup();
+
+    const query: TypedDocumentNode<Data, Variables> = gql`
+      query TodosQuery($offset: Int!) {
+        todos(offset: $offset) {
+          id
+          name
+          completed
+        }
+      }
+    `;
+
+    const mocks: MockedResponse<Data, Variables>[] = [
+      {
+        request: { query, variables: { offset: 0 } },
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "1",
+                name: "Clean room",
+                completed: false,
+              },
+            ],
+          },
+        },
+        delay: 10,
+      },
+      {
+        request: { query, variables: { offset: 1 } },
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "2",
+                name: "Take out trash",
+                completed: true,
+              },
+            ],
+          },
+        },
+        delay: 10,
+      },
+    ];
+
+    const Profiler = createProfiler({
+      initialSnapshot: {
+        isPending: false,
+        result: null as Pick<
+          UseSuspenseQueryResult<Data>,
+          "data" | "error" | "networkStatus"
+        > | null,
+      },
+    });
+
+    function SuspenseFallback() {
+      useTrackRenders();
+
+      return <div>Loading...</div>;
+    }
+
+    const client = new ApolloClient({
+      link: new MockLink(mocks),
+      cache: new InMemoryCache({
+        typePolicies: {
+          Query: {
+            fields: {
+              todos: offsetLimitPagination(),
+            },
+          },
+        },
+      }),
+      defaultOptions: {
+        watchQuery: {
+          errorPolicy: "all",
+        },
+      },
+    });
+
+    function App() {
+      useTrackRenders();
+      const [isPending, startTransition] = React.useTransition();
+      const { data, error, networkStatus, fetchMore } = useSuspenseQuery(
+        query,
+        {
+          variables: { offset: 0 },
+        }
+      );
+
+      Profiler.mergeSnapshot({
+        isPending,
+        result: { data, error, networkStatus },
+      });
+
+      return (
+        <button
+          onClick={() => {
+            startTransition(() => {
+              fetchMore({ variables: { offset: 1 } });
+            });
+          }}
+        >
+          Load more
+        </button>
+      );
+    }
+
+    render(<App />, {
+      wrapper: ({ children }) => (
+        <ApolloProvider client={client}>
+          <Profiler>
+            <Suspense fallback={<SuspenseFallback />}>{children}</Suspense>
+          </Profiler>
+        </ApolloProvider>
+      ),
+    });
+
+    {
+      const { renderedComponents } = await Profiler.takeRender();
+
+      expect(renderedComponents).toStrictEqual([SuspenseFallback]);
+    }
+
+    {
+      const { snapshot } = await Profiler.takeRender();
+
+      expect(snapshot).toEqual({
+        isPending: false,
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "1",
+                name: "Clean room",
+                completed: false,
+              },
+            ],
+          },
+          error: undefined,
+          networkStatus: NetworkStatus.ready,
+        },
+      });
+    }
+
+    await act(() => user.click(screen.getByText("Load more")));
+
+    {
+      const { snapshot, renderedComponents } = await Profiler.takeRender();
+
+      expect(renderedComponents).toStrictEqual([App]);
+      expect(snapshot).toEqual({
+        isPending: true,
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "1",
+                name: "Clean room",
+                completed: false,
+              },
+            ],
+          },
+          error: undefined,
+          networkStatus: NetworkStatus.ready,
+        },
+      });
+    }
+
+    {
+      const { snapshot, renderedComponents } = await Profiler.takeRender();
+
+      expect(renderedComponents).toStrictEqual([App]);
+      expect(snapshot).toEqual({
+        isPending: false,
+        result: {
+          data: {
+            todos: [
+              {
+                __typename: "Todo",
+                id: "1",
+                name: "Clean room",
+                completed: false,
+              },
+              {
+                __typename: "Todo",
+                id: "2",
+                name: "Take out trash",
+                completed: true,
+              },
+            ],
+          },
+          error: undefined,
+          networkStatus: NetworkStatus.ready,
+        },
+      });
+    }
+
+    await expect(Profiler).not.toRerender();
+  });
+
   // https://github.com/apollographql/apollo-client/issues/11642
   it("returns merged array when `fetchMore` returns empty array of results", async () => {
     const query: TypedDocumentNode<PaginatedCaseData, PaginatedCaseVariables> =
diff --git a/src/react/internal/cache/QueryReference.ts b/src/react/internal/cache/QueryReference.ts
index 110a0823bb8..68efe9272b7 100644
--- a/src/react/internal/cache/QueryReference.ts
+++ b/src/react/internal/cache/QueryReference.ts
@@ -253,6 +253,7 @@ export class InternalQueryReference<TData = unknown> {
   didChangeOptions(watchQueryOptions: ObservedOptions) {
     return OBSERVED_CHANGED_OPTIONS.some(
       (option) =>
+        option in watchQueryOptions &&
         !equal(this.watchQueryOptions[option], watchQueryOptions[option])
     );
   }