diff --git a/test/test_solvers.py b/test/test_solvers.py
index a0c1d7c43..b1bd097a3 100644
--- a/test/test_solvers.py
+++ b/test/test_solvers.py
@@ -432,55 +432,82 @@ def test_solve_gromov_grid(nx, reg, reg_type, unbalanced, unbalanced_type, alpha
     M = np.random.rand(n_samples_s, n_samples_t)
 
     try:
-        sol0 = ot.solve_gromov(
-            Ca,
-            Cb,
-            reg=reg,
-            reg_type=reg_type,
-            unbalanced=unbalanced,
-            unbalanced_type=unbalanced_type,
-            loss=loss,
-        )  # GW
-        sol0_fgw = ot.solve_gromov(
-            Ca,
-            Cb,
-            M,
-            reg=reg,
-            reg_type=reg_type,
-            unbalanced=unbalanced,
-            unbalanced_type=unbalanced_type,
-            alpha=alpha,
-            loss=loss,
-        )  # FGW
-
-        # solve in backend
-        ax, bx, Mx, Cax, Cbx = nx.from_numpy(a, b, M, Ca, Cb)
+        if unbalanced_type == "partial" and unbalanced is None:
+            ax, bx, Mx, Cax, Cbx = nx.from_numpy(a, b, M, Ca, Cb)
+
+            with pytest.raises(ValueError):
+                solx = ot.solve_gromov(
+                    Cax,
+                    Cbx,
+                    reg=reg,
+                    reg_type=reg_type,
+                    unbalanced=unbalanced,
+                    unbalanced_type=unbalanced_type,
+                    loss=loss,
+                )  # GW
+            with pytest.raises(ValueError):
+                solx_fgw = ot.solve_gromov(
+                    Cax,
+                    Cbx,
+                    Mx,
+                    reg=reg,
+                    reg_type=reg_type,
+                    unbalanced=unbalanced,
+                    unbalanced_type=unbalanced_type,
+                    alpha=alpha,
+                    loss=loss,
+                )  # FGW
 
-        solx = ot.solve_gromov(
-            Cax,
-            Cbx,
-            reg=reg,
-            reg_type=reg_type,
-            unbalanced=unbalanced,
-            unbalanced_type=unbalanced_type,
-            loss=loss,
-        )  # GW
-        solx_fgw = ot.solve_gromov(
-            Cax,
-            Cbx,
-            Mx,
-            reg=reg,
-            reg_type=reg_type,
-            unbalanced=unbalanced,
-            unbalanced_type=unbalanced_type,
-            alpha=alpha,
-            loss=loss,
-        )  # FGW
-
-        solx.value_quad
-
-        assert_allclose_sol(sol0, solx)
-        assert_allclose_sol(sol0_fgw, solx_fgw)
+        else:
+            sol0 = ot.solve_gromov(
+                Ca,
+                Cb,
+                reg=reg,
+                reg_type=reg_type,
+                unbalanced=unbalanced,
+                unbalanced_type=unbalanced_type,
+                loss=loss,
+            )  # GW
+            sol0_fgw = ot.solve_gromov(
+                Ca,
+                Cb,
+                M,
+                reg=reg,
+                reg_type=reg_type,
+                unbalanced=unbalanced,
+                unbalanced_type=unbalanced_type,
+                alpha=alpha,
+                loss=loss,
+            )  # FGW
+
+            # solve in backend
+            ax, bx, Mx, Cax, Cbx = nx.from_numpy(a, b, M, Ca, Cb)
+
+            solx = ot.solve_gromov(
+                Cax,
+                Cbx,
+                reg=reg,
+                reg_type=reg_type,
+                unbalanced=unbalanced,
+                unbalanced_type=unbalanced_type,
+                loss=loss,
+            )  # GW
+            solx_fgw = ot.solve_gromov(
+                Cax,
+                Cbx,
+                Mx,
+                reg=reg,
+                reg_type=reg_type,
+                unbalanced=unbalanced,
+                unbalanced_type=unbalanced_type,
+                alpha=alpha,
+                loss=loss,
+            )  # FGW
+
+            solx.value_quad
+
+            assert_allclose_sol(sol0, solx)
+            assert_allclose_sol(sol0_fgw, solx_fgw)
 
     except NotImplementedError:
         pytest.skip("Not implemented")