diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c
index 354eb0d4e6..8c024773af 100644
--- a/src/backend/partitioning/partprune.c
+++ b/src/backend/partitioning/partprune.c
@@ -2048,8 +2048,12 @@ get_matching_hash_bounds(PartitionPruneContext *context,
 				bms_make_singleton(rowHash % greatest_modulus);
 	}
 	else
+	{
+		/* Getting here means at least one hash partition exists. */
+		Assert(boundinfo->ndatums > 0);
 		result->bound_offsets = bms_add_range(NULL, 0,
 											  boundinfo->ndatums - 1);
+	}
 
 	/*
 	 * There is neither a special hash null partition or the default hash
@@ -2995,7 +2999,11 @@ perform_pruning_combine_step(PartitionPruneContext *context,
 	{
 		PartitionBoundInfo boundinfo = context->boundinfo;
 
-		result->bound_offsets = bms_add_range(NULL, 0, boundinfo->ndatums - 1);
+		if (boundinfo->ndatums > 0)
+			result->bound_offsets = bms_add_range(NULL, 0,
+												  boundinfo->ndatums - 1);
+		else
+			result->bound_offsets = NULL;
 		result->scan_default = partition_bound_has_default(boundinfo);
 		result->scan_null = partition_bound_accepts_nulls(boundinfo);
 		return result;