diff --git a/src/compiler/nir/nir_passthrough_gs.c b/src/compiler/nir/nir_passthrough_gs.c
index d895d6c0f3e..04a3adae1b5 100644
--- a/src/compiler/nir/nir_passthrough_gs.c
+++ b/src/compiler/nir/nir_passthrough_gs.c
@@ -34,7 +34,7 @@ gs_in_prim_for_topology(enum mesa_prim prim)
    case MESA_PRIM_QUADS:
       return MESA_PRIM_LINES_ADJACENCY;
    default:
-      return prim;
+      return u_decomposed_prim(prim);
    }
 }