diff --git a/src/grdview.c b/src/grdview.c
index 1c1fa1e8d2a..c04a7df4b3e 100644
--- a/src/grdview.c
+++ b/src/grdview.c
@@ -1073,7 +1073,7 @@ EXTERN_MSC int GMT_grdview(void *V_API, int mode, void *args) {
 			Return (API->error);
 		}
 		if (P->is_bw) Ctrl->Q.monochrome = true;
-		if (P->categorical && !(Ctrl->Q.mode == GRDVIEW_MESH || Ctrl->T.active)) {
+		if (P->categorical && !(Ctrl->Q.mode == GRDVIEW_MESH || Ctrl->Q.special || Ctrl->T.active)) {
 			GMT_Report (API, GMT_MSG_ERROR, "Categorical data (as implied by CPT) cannot be interpolated and require -T or just -Qm.\n");
 			Return (GMT_RUNTIME_ERROR);
 		}