diff --git a/apps/api/src/auth/auth.service.spec.ts b/apps/api/src/auth/auth.service.spec.ts
index 24e6d3d..56d0f56 100644
--- a/apps/api/src/auth/auth.service.spec.ts
+++ b/apps/api/src/auth/auth.service.spec.ts
@@ -278,7 +278,7 @@ describe("AuthService", () => {
 
       expect(loggerError).toHaveBeenCalledTimes(1);
       expect(loggerError).toHaveBeenCalledWith(
-        expect.stringContaining("OIDC provider unreachable"),
+        expect.stringContaining("OIDC provider unreachable")
       );
     });
 
@@ -305,7 +305,7 @@ describe("AuthService", () => {
 
       expect(loggerError).toHaveBeenCalledTimes(1);
       expect(loggerError).toHaveBeenCalledWith(
-        expect.stringContaining("OIDC provider returned non-OK status"),
+        expect.stringContaining("OIDC provider returned non-OK status")
       );
     });
 
@@ -332,7 +332,7 @@ describe("AuthService", () => {
 
       expect(result).toBe(true);
       expect(loggerLog).toHaveBeenCalledWith(
-        expect.stringContaining("OIDC provider recovered after 2 consecutive failure(s)"),
+        expect.stringContaining("OIDC provider recovered after 2 consecutive failure(s)")
       );
       // Verify counter reset
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -495,6 +495,26 @@ describe("AuthService", () => {
       expect(result).toBeNull();
     });
 
+    it("should return null when getSession throws a non-Error value (string)", async () => {
+      const auth = service.getAuth();
+      const mockGetSession = vi.fn().mockRejectedValue("some error");
+      auth.api = { getSession: mockGetSession } as any;
+
+      const result = await service.verifySession("any-token");
+
+      expect(result).toBeNull();
+    });
+
+    it("should return null when getSession throws a non-Error value (object)", async () => {
+      const auth = service.getAuth();
+      const mockGetSession = vi.fn().mockRejectedValue({ code: "ERR_UNKNOWN" });
+      auth.api = { getSession: mockGetSession } as any;
+
+      const result = await service.verifySession("any-token");
+
+      expect(result).toBeNull();
+    });
+
     it("should re-throw unexpected errors that are not known auth errors", async () => {
       const auth = service.getAuth();
       const mockGetSession = vi.fn().mockRejectedValue(new Error("Verification failed"));
diff --git a/apps/web/src/lib/auth/auth-context.test.tsx b/apps/web/src/lib/auth/auth-context.test.tsx
index ab92a15..d0c88dd 100644
--- a/apps/web/src/lib/auth/auth-context.test.tsx
+++ b/apps/web/src/lib/auth/auth-context.test.tsx
@@ -158,6 +158,104 @@ describe("AuthContext", (): void => {
     expect(apiPost).toHaveBeenCalledWith("/auth/sign-out");
   });
 
+  it("should clear user and set authError to 'network' when signOut fails with a network error", async (): Promise<void> => {
+    const consoleErrorSpy = vi.spyOn(console, "error").mockImplementation(() => {
+      // Intentionally empty - suppressing log output in tests
+    });
+
+    const mockUser: AuthUser = {
+      id: "user-1",
+      email: "test@example.com",
+      name: "Test User",
+    };
+
+    // First: user is logged in
+    vi.mocked(apiGet).mockResolvedValueOnce({
+      user: mockUser,
+      session: { id: "session-1", token: "token123", expiresAt: futureExpiry() },
+    });
+
+    // signOut request fails with a network error (TypeError with "fetch")
+    vi.mocked(apiPost).mockRejectedValueOnce(new TypeError("Failed to fetch"));
+
+    render(
+      <AuthProvider>
+        <TestComponent />
+      </AuthProvider>
+    );
+
+    // Wait for authenticated state
+    await waitFor(() => {
+      expect(screen.getByTestId("auth-status")).toHaveTextContent("Authenticated");
+    });
+
+    // Click sign out — the apiPost will reject
+    const signOutButton = screen.getByRole("button", { name: "Sign Out" });
+    signOutButton.click();
+
+    // User should be cleared (finally block runs even on error)
+    await waitFor(() => {
+      expect(screen.getByTestId("auth-status")).toHaveTextContent("Not Authenticated");
+    });
+
+    // authError should be set to "network" via classifyAuthError
+    expect(screen.getByTestId("auth-error")).toHaveTextContent("network");
+
+    // Verify the sign-out endpoint was still called
+    expect(apiPost).toHaveBeenCalledWith("/auth/sign-out");
+
+    consoleErrorSpy.mockRestore();
+  });
+
+  it("should clear user and set authError to 'backend' when signOut fails with a server error", async (): Promise<void> => {
+    const consoleErrorSpy = vi.spyOn(console, "error").mockImplementation(() => {
+      // Intentionally empty - suppressing log output in tests
+    });
+
+    const mockUser: AuthUser = {
+      id: "user-1",
+      email: "test@example.com",
+      name: "Test User",
+    };
+
+    // First: user is logged in
+    vi.mocked(apiGet).mockResolvedValueOnce({
+      user: mockUser,
+      session: { id: "session-1", token: "token123", expiresAt: futureExpiry() },
+    });
+
+    // signOut request fails with a 500 Internal Server Error
+    vi.mocked(apiPost).mockRejectedValueOnce(new Error("Internal Server Error"));
+
+    render(
+      <AuthProvider>
+        <TestComponent />
+      </AuthProvider>
+    );
+
+    // Wait for authenticated state
+    await waitFor(() => {
+      expect(screen.getByTestId("auth-status")).toHaveTextContent("Authenticated");
+    });
+
+    // Click sign out — the apiPost will reject with server error
+    const signOutButton = screen.getByRole("button", { name: "Sign Out" });
+    signOutButton.click();
+
+    // User should be cleared (finally block runs even on error)
+    await waitFor(() => {
+      expect(screen.getByTestId("auth-status")).toHaveTextContent("Not Authenticated");
+    });
+
+    // authError should be set to "backend" via classifyAuthError
+    expect(screen.getByTestId("auth-error")).toHaveTextContent("backend");
+
+    // Verify the sign-out endpoint was still called
+    expect(apiPost).toHaveBeenCalledWith("/auth/sign-out");
+
+    consoleErrorSpy.mockRestore();
+  });
+
   it("should throw error when useAuth is used outside AuthProvider", (): void => {
     // Suppress console.error for this test
     const consoleErrorSpy = vi.spyOn(console, "error").mockImplementation(() => {