diff --git a/src/backend/distributed/master/master_stage_protocol.c b/src/backend/distributed/master/master_stage_protocol.c
index 2f964d603..d39b46446 100644
--- a/src/backend/distributed/master/master_stage_protocol.c
+++ b/src/backend/distributed/master/master_stage_protocol.c
@@ -839,7 +839,7 @@ WorkerShardStats(ShardPlacement *placement, Oid relationId, char *shardName,
 	}
 
 	errno = 0;
-	tableSize = strtoull(tableSizeString, &tableSizeStringEnd, 0);
+	tableSize = pg_strtouint64(tableSizeString, &tableSizeStringEnd, 0);
 	if (errno != 0 || (*tableSizeStringEnd) != '\0')
 	{
 		PQclear(queryResult);
diff --git a/src/backend/distributed/utils/citus_readfuncs.c b/src/backend/distributed/utils/citus_readfuncs.c
index 4e8ddb1ef..a06577477 100644
--- a/src/backend/distributed/utils/citus_readfuncs.c
+++ b/src/backend/distributed/utils/citus_readfuncs.c
@@ -19,6 +19,7 @@
 #include "distributed/multi_server_executor.h"
 #include "nodes/parsenodes.h"
 #include "nodes/readfuncs.h"
+#include "utils/builtins.h"
 
 
 /*
@@ -158,7 +159,7 @@ CitusSetTag(Node *node, int tag)
 #define atooid(x)  ((Oid) strtoul((x), NULL, 10))
 
 /* XXX: Citus */
-#define atoull(x)  ((uint64) strtoull((x), NULL, 10))
+#define atoull(x)  ((uint64) pg_strtouint64((x), NULL, 10))
 
 #define strtobool(x)  ((*(x) == 't') ? true : false)
 
diff --git a/src/backend/distributed/worker/worker_data_fetch_protocol.c b/src/backend/distributed/worker/worker_data_fetch_protocol.c
index fdb82c56c..41b1c8635 100644
--- a/src/backend/distributed/worker/worker_data_fetch_protocol.c
+++ b/src/backend/distributed/worker/worker_data_fetch_protocol.c
@@ -784,19 +784,14 @@ ExtractShardId(const char *tableName)
 	}
 	shardIdString++;
 
-#ifdef HAVE_STRTOULL
 	errno = 0;
-	shardId = strtoull(shardIdString, &shardIdStringEnd, 0);
+	shardId = pg_strtouint64(shardIdString, &shardIdStringEnd, 0);
 
 	if (errno != 0 || (*shardIdStringEnd != '\0'))
 	{
 		ereport(ERROR, (errmsg("could not extract shardId from table name \"%s\"",
 							   tableName)));
 	}
-#else
-	ereport(ERROR, (errmsg("could not extract shardId from table name"),
-					errhint("Your platform does not support strtoull()")));
-#endif
 
 	return shardId;
 }