diff --git a/src/backend/distributed/planner/multi_physical_planner.c b/src/backend/distributed/planner/multi_physical_planner.c
index 64d7a5f16..b34c36b4c 100644
--- a/src/backend/distributed/planner/multi_physical_planner.c
+++ b/src/backend/distributed/planner/multi_physical_planner.c
@@ -110,6 +110,8 @@ static MapMergeJob * BuildMapMergeJob(Query *jobQuery, List *dependedJobList,
 									  Oid baseRelationId,
 									  BoundaryNodeJobType boundaryNodeJobType);
 static uint32 HashPartitionCount(void);
+static int CompareShardIntervals(const void *leftElement, const void *rightElement,
+								 FmgrInfo *typeCompareFunction);
 static ArrayType * SplitPointObject(ShardInterval **shardIntervalArray,
 									uint32 shardIntervalCount);
 
@@ -167,6 +169,7 @@ static List * RoundRobinAssignTaskList(List *taskList);
 static List * RoundRobinReorder(Task *task, List *placementList);
 static List * ReorderAndAssignTaskList(List *taskList,
 									   List * (*reorderFunction)(Task *, List *));
+static int CompareTasksByShardId(const void *leftElement, const void *rightElement);
 static List * ActiveShardPlacementLists(List *taskList);
 static List * ActivePlacementList(List *placementList);
 static List * LeftRotateList(List *list, uint32 rotateCount);
@@ -1807,7 +1810,7 @@ SortedShardIntervalArray(List *shardIntervalList)
  * CompareShardIntervals acts as a helper function to compare two shard interval
  * pointers by their minimum values, using the value's type comparison function.
  */
-int
+static int
 CompareShardIntervals(const void *leftElement, const void *rightElement,
 					  FmgrInfo *typeCompareFunction)
 {
@@ -5070,7 +5073,7 @@ ReorderAndAssignTaskList(List *taskList, List * (*reorderFunction)(Task *, List
 
 
 /* Helper function to compare two tasks by their anchor shardId. */
-int
+static int
 CompareTasksByShardId(const void *leftElement, const void *rightElement)
 {
 	const Task *leftTask = *((const Task **) leftElement);
diff --git a/src/include/distributed/multi_physical_planner.h b/src/include/distributed/multi_physical_planner.h
index 92bcd1354..3ad053b22 100644
--- a/src/include/distributed/multi_physical_planner.h
+++ b/src/include/distributed/multi_physical_planner.h
@@ -238,8 +238,6 @@ extern int CompareShardPlacements(const void *leftElement, const void *rightElem
 extern ShardInterval ** SortedShardIntervalArray(List *shardList);
 extern bool ShardIntervalsOverlap(ShardInterval *firstInterval,
 								  ShardInterval *secondInterval);
-extern int CompareShardIntervals(const void *leftElement, const void *rightElement,
-								 FmgrInfo *typeCompareFunction);
 
 /* function declarations for Task and Task list operations */
 extern bool TasksEqual(const Task *a, const Task *b);
@@ -249,7 +247,6 @@ extern bool TaskListMember(const List *taskList, const Task *task);
 extern List * TaskListDifference(const List *list1, const List *list2);
 extern List * TaskListUnion(const List *list1, const List *list2);
 extern List * FirstReplicaAssignTaskList(List *taskList);
-extern int CompareTasksByShardId(const void *leftElement, const void *rightElement);
 
 
 #endif   /* MULTI_PHYSICAL_PLANNER_H */