diff --git a/src/hnswbuild.c b/src/hnswbuild.c
index cd323c5..0bc4ca7 100644
--- a/src/hnswbuild.c
+++ b/src/hnswbuild.c
@@ -178,7 +178,7 @@ CreateGraphPages(HnswBuildState * buildstate)
 		iter = element->next;
 
 		/* Zero memory for each element */
-		MemSet(etup, 0, HNSW_TUPLE_ALLOC_SIZE);
+		memset(etup, 0, HNSW_TUPLE_ALLOC_SIZE);
 
 		/* Calculate sizes */
 		etupSize = HNSW_ELEMENT_TUPLE_SIZE(VARSIZE_ANY(valuePtr));
@@ -266,7 +266,7 @@ WriteNeighborTuples(HnswBuildState * buildstate)
 		iter = element->next;
 
 		/* Zero memory for each element */
-		MemSet(ntup, 0, HNSW_TUPLE_ALLOC_SIZE);
+		memset(ntup, 0, HNSW_TUPLE_ALLOC_SIZE);
 
 		/* Can take a while, so ensure we can interrupt */
 		/* Needs to be called when no buffer locks are held */
diff --git a/src/hnswvacuum.c b/src/hnswvacuum.c
index eb993ca..d15766a 100644
--- a/src/hnswvacuum.c
+++ b/src/hnswvacuum.c
@@ -249,7 +249,7 @@ RepairGraphElement(HnswVacuumState * vacuumstate, HnswElement element, HnswEleme
 	HnswFindElementNeighbors(base, element, entryPoint, index, support, m, efConstruction, true);
 
 	/* Zero memory for each element */
-	MemSet(ntup, 0, HNSW_TUPLE_ALLOC_SIZE);
+	memset(ntup, 0, HNSW_TUPLE_ALLOC_SIZE);
 
 	/* Update neighbor tuple */
 	/* Do this before getting page to minimize locking */
diff --git a/src/ivfbuild.c b/src/ivfbuild.c
index ec12dc2..044d0a7 100644
--- a/src/ivfbuild.c
+++ b/src/ivfbuild.c
@@ -523,7 +523,7 @@ CreateListPages(Relation index, VectorArray centers, int lists,
 		OffsetNumber offno;
 
 		/* Zero memory for each list */
-		MemSet(list, 0, listSize);
+		memset(list, 0, listSize);
 
 		/* Load list */
 		list->startPage = InvalidBlockNumber;