diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 39e7234e3ac..11e0ee96a1d 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -1983,7 +1983,7 @@ ExplainNode(PlanState *planstate, List *ancestors,
 				show_instrumentation_count("Rows Removed by Filter", 1,
 										   planstate, es);
 			if (es->analyze)
-				show_indexscan_nprimscans(planstate, es);
+				show_indexscan_nprimscans(((IndexScanState *) planstate)->iss_ScanDesc, es);
 			break;
 		case T_IndexOnlyScan:
 			show_scan_qual(((IndexOnlyScan *) plan)->indexqual,
@@ -2001,14 +2001,14 @@ ExplainNode(PlanState *planstate, List *ancestors,
 			{
 				ExplainPropertyFloat("Heap Fetches", NULL,
 									 planstate->instrument->ntuples2, 0, es);
-				show_indexscan_nprimscans(planstate, es);
+				show_indexscan_nprimscans(((IndexOnlyScanState *) planstate)->iss_ScanDesc, es);
 			}
 			break;
 		case T_BitmapIndexScan:
 			show_scan_qual(((BitmapIndexScan *) plan)->indexqualorig,
 						   "Index Cond", planstate, ancestors, es);
 			if (es->analyze)
-				show_indexscan_nprimscans(planstate, es);
+				show_indexscan_nprimscans(((BitmapIndexScanState *) planstate)->iss_ScanDesc, es);
 			break;
 		case T_BitmapHeapScan:
 			show_scan_qual(((BitmapHeapScan *) plan)->bitmapqualorig,
@@ -2523,26 +2523,8 @@ show_expression(Node *node, const char *qlabel,
  * IndexOnlyScan node, or BitmapIndexScan node
  */
 static void
-show_indexscan_nprimscans(PlanState *planstate, ExplainState *es)
+show_indexscan_nprimscans(IndexScanDescData *scanDesc, ExplainState *es)
 {
-	Plan	   *plan = planstate->plan;
-	struct IndexScanDescData *scanDesc = NULL;
-
-	switch (nodeTag(plan))
-	{
-		case T_IndexScan:
-			scanDesc = ((IndexScanState *) planstate)->iss_ScanDesc;
-			break;
-		case T_IndexOnlyScan:
-			scanDesc = ((IndexOnlyScanState *) planstate)->ioss_ScanDesc;
-			break;
-		case T_BitmapIndexScan:
-			scanDesc = ((BitmapIndexScanState *) planstate)->biss_ScanDesc;
-			break;
-		default:
-			break;
-	}
-
 	if (scanDesc && scanDesc->nprimscans > 0)
 		ExplainPropertyUInteger("Primitive Index Scans", NULL,
 								scanDesc->nprimscans, es);