diff --git a/src/ivfkmeans.c b/src/ivfkmeans.c
index 65d312b..7c55bee 100644
--- a/src/ivfkmeans.c
+++ b/src/ivfkmeans.c
@@ -89,33 +89,27 @@ InitCenters(Relation index, VectorArray samples, VectorArray centers, float *low
 }
 
 /*
- * Apply norm to vector
+ * Norm centers
  */
-static inline void
-ApplyNorm(FmgrInfo *normprocinfo, Oid collation, Datum value, IvfflatType type)
+static void
+NormCenters(FmgrInfo *normalizeprocinfo, Oid collation, VectorArray centers)
 {
-	double		norm = DatumGetFloat8(FunctionCall1Coll(normprocinfo, collation, value));
+	MemoryContext normCtx = AllocSetContextCreate(CurrentMemoryContext,
+												  "Ivfflat norm temporary context",
+												  ALLOCSET_DEFAULT_SIZES);
+	MemoryContext oldCtx = MemoryContextSwitchTo(normCtx);
 
-	/* TODO Handle zero norm */
-	if (norm > 0)
+	for (int j = 0; j < centers->maxlen; j++)
 	{
-		if (type == IVFFLAT_TYPE_VECTOR)
-		{
-			Vector	   *vec = DatumGetVector(value);
+		Datum		center = PointerGetDatum(VectorArrayGet(centers, j));
+		Datum		newCenter = IvfflatNormValue(normalizeprocinfo, collation, center);
 
-			for (int i = 0; i < vec->dim; i++)
-				vec->x[i] /= norm;
-		}
-		else if (type == IVFFLAT_TYPE_HALFVEC)
-		{
-			HalfVector *vec = DatumGetHalfVector(value);
-
-			for (int i = 0; i < vec->dim; i++)
-				vec->x[i] = Float4ToHalfUnchecked(HalfToFloat4(vec->x[i]) / norm);
-		}
-		else
-			elog(ERROR, "Unsupported type");
+		memcpy(DatumGetPointer(center), DatumGetPointer(newCenter), VARSIZE_ANY(DatumGetPointer(newCenter)));
+		MemoryContextReset(normCtx);
 	}
+
+	MemoryContextSwitchTo(oldCtx);
+	MemoryContextDelete(normCtx);
 }
 
 /*
@@ -154,6 +148,7 @@ QuickCenters(Relation index, VectorArray samples, VectorArray centers, IvfflatTy
 	int			dimensions = centers->dim;
 	Oid			collation = index->rd_indcollation[0];
 	FmgrInfo   *normprocinfo = IvfflatOptionalProcInfo(index, IVFFLAT_KMEANS_NORM_PROC);
+	FmgrInfo   *normalizeprocinfo = IvfflatOptionalProcInfo(index, IVFFLAT_NORMALIZE_PROC);
 
 	/* Copy existing vectors while avoiding duplicates */
 	if (samples->length > 0)
@@ -217,12 +212,12 @@ QuickCenters(Relation index, VectorArray samples, VectorArray centers, IvfflatTy
 		else
 			elog(ERROR, "Unsupported type");
 
-		/* Normalize if needed (only needed for random centers) */
-		if (normprocinfo != NULL)
-			ApplyNorm(normprocinfo, collation, center, type);
-
 		centers->length++;
 	}
+
+	/* Fine if existing vectors are normalized twice */
+	if (normprocinfo != NULL)
+		NormCenters(normalizeprocinfo, collation, centers);
 }
 
 #ifdef IVFFLAT_MEMORY
@@ -246,7 +241,7 @@ ShowMemoryUsage(MemoryContext context, Size estimatedSize)
  * Compute new centers
  */
 static void
-ComputeNewCenters(VectorArray samples, VectorArray aggCenters, VectorArray newCenters, int *centerCounts, int *closestCenters, FmgrInfo *normprocinfo, Oid collation, IvfflatType type)
+ComputeNewCenters(VectorArray samples, VectorArray aggCenters, VectorArray newCenters, int *centerCounts, int *closestCenters, FmgrInfo *normprocinfo, FmgrInfo *normalizeprocinfo, Oid collation, IvfflatType type)
 {
 	int			dimensions = aggCenters->dim;
 	int			numCenters = aggCenters->maxlen;
@@ -360,14 +355,7 @@ ComputeNewCenters(VectorArray samples, VectorArray aggCenters, VectorArray newCe
 
 	/* Normalize if needed */
 	if (normprocinfo != NULL)
-	{
-		for (int j = 0; j < numCenters; j++)
-		{
-			Datum		newCenter = PointerGetDatum(VectorArrayGet(newCenters, j));
-
-			ApplyNorm(normprocinfo, collation, newCenter, type);
-		}
-	}
+		NormCenters(normalizeprocinfo, collation, newCenters);
 }
 
 /*
@@ -383,6 +371,7 @@ ElkanKmeans(Relation index, VectorArray samples, VectorArray centers, IvfflatTyp
 {
 	FmgrInfo   *procinfo;
 	FmgrInfo   *normprocinfo;
+	FmgrInfo   *normalizeprocinfo;
 	Oid			collation;
 	int			dimensions = centers->dim;
 	int			numCenters = centers->maxlen;
@@ -430,6 +419,7 @@ ElkanKmeans(Relation index, VectorArray samples, VectorArray centers, IvfflatTyp
 	/* Set support functions */
 	procinfo = index_getprocinfo(index, 1, IVFFLAT_KMEANS_DISTANCE_PROC);
 	normprocinfo = IvfflatOptionalProcInfo(index, IVFFLAT_KMEANS_NORM_PROC);
+	normalizeprocinfo = IvfflatOptionalProcInfo(index, IVFFLAT_NORMALIZE_PROC);
 	collation = index->rd_indcollation[0];
 
 	/* Use memory context */
@@ -627,7 +617,7 @@ ElkanKmeans(Relation index, VectorArray samples, VectorArray centers, IvfflatTyp
 		}
 
 		/* Step 4: For each center c, let m(c) be mean of all points assigned */
-		ComputeNewCenters(samples, aggCenters, newCenters, centerCounts, closestCenters, normprocinfo, collation, type);
+		ComputeNewCenters(samples, aggCenters, newCenters, centerCounts, closestCenters, normprocinfo, normalizeprocinfo, collation, type);
 
 		/* Step 5 */
 		for (int j = 0; j < numCenters; j++)