diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 08239dde4f..634ca86cfb 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -719,6 +719,9 @@ buildIndexArray(void *objArray, int numObjs, Size objSize)
 	DumpableObject **ptrs;
 	int			i;
 
+	if (numObjs <= 0)
+		return NULL;
+
 	ptrs = (DumpableObject **) pg_malloc(numObjs * sizeof(DumpableObject *));
 	for (i = 0; i < numObjs; i++)
 		ptrs[i] = (DumpableObject *) ((char *) objArray + i * objSize);