diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index 3493a5374a1..1047b48eb70 100644
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -5543,6 +5543,7 @@ accumArrayResultArr(ArrayBuildStateArr *astate,
 				ndatabytes;
 	char	   *data;
 	int			i;
+	int			newnitems;
 
 	/*
 	 * We disallow accumulating null subarrays.  Another plausible definition
@@ -5572,6 +5573,14 @@ accumArrayResultArr(ArrayBuildStateArr *astate,
 	nitems = ArrayGetNItems(ndims, dims);
 	ndatabytes = ARR_SIZE(arg) - ARR_DATA_OFFSET(arg);
 
+	/* Check that the array doesn't grow too large */
+	newnitems = astate->nitems + nitems;
+	if (newnitems > MaxArraySize)
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("array size exceeds the maximum allowed (%zu)",
+						MaxArraySize)));
+
 	if (astate->ndims == 0)
 	{
 		/* First input; check/save the dimensionality info */
@@ -5637,8 +5646,6 @@ accumArrayResultArr(ArrayBuildStateArr *astate,
 	/* Deal with null bitmap if needed */
 	if (astate->nullbitmap || ARR_HASNULL(arg))
 	{
-		int			newnitems = astate->nitems + nitems;
-
 		if (astate->nullbitmap == NULL)
 		{
 			/*
@@ -5662,7 +5669,7 @@ accumArrayResultArr(ArrayBuildStateArr *astate,
 						  nitems);
 	}
 
-	astate->nitems += nitems;
+	astate->nitems = newnitems;
 	astate->dims[0] += 1;
 
 	MemoryContextSwitchTo(oldcontext);