diff --git a/collection.go b/collection.go
index 2a8a5a0..3e2efc4 100644
--- a/collection.go
+++ b/collection.go
@@ -225,7 +225,7 @@ func (c *Collection) AddDocument(ctx context.Context, doc Document) error {
 		doc.Embedding = embedding
 	} else {
 		if !isNormalized(doc.Embedding) {
-			doc.Embedding = normalizeVector(doc.Embedding)
+			normalizeVectorInPlace(doc.Embedding)
 		}
 	}
 
diff --git a/collection_test.go b/collection_test.go
index c652655..3db67d3 100644
--- a/collection_test.go
+++ b/collection_test.go
@@ -567,7 +567,7 @@ func benchmarkCollection_Query(b *testing.B, n int, withContent bool) {
 		qv[j] = r.Float32()
 	}
 	// The document embeddings are normalized, so the query must be normalized too.
-	qv = normalizeVector(qv)
+	normalizeVectorInPlace(qv)
 
 	// Create collection
 	db := NewDB()
@@ -590,7 +590,7 @@ func benchmarkCollection_Query(b *testing.B, n int, withContent bool) {
 		for j := 0; j < d; j++ {
 			v[j] = r.Float32()
 		}
-		v = normalizeVector(v)
+		normalizeVectorInPlace(v)
 
 		// Add document with some metadata and content depending on parameter.
 		// When providing embeddings, the embedding func is not called.
diff --git a/embed_cohere.go b/embed_cohere.go
index 0891924..5bee627 100644
--- a/embed_cohere.go
+++ b/embed_cohere.go
@@ -159,7 +159,7 @@ func NewEmbeddingFuncCohere(apiKey string, model EmbeddingModelCohere) Embedding
 			}
 		})
 		if !checkedNormalized {
-			v = normalizeVector(v)
+			normalizeVectorInPlace(v)
 		}
 
 		return v, nil
diff --git a/embed_ollama.go b/embed_ollama.go
index 019c669..f2bfb2f 100644
--- a/embed_ollama.go
+++ b/embed_ollama.go
@@ -91,7 +91,7 @@ func NewEmbeddingFuncOllama(model string, baseURLOllama string) EmbeddingFunc {
 			}
 		})
 		if !checkedNormalized {
-			v = normalizeVector(v)
+			normalizeVectorInPlace(v)
 		}
 
 		return v, nil
diff --git a/embed_openai.go b/embed_openai.go
index de3de82..d302fc0 100644
--- a/embed_openai.go
+++ b/embed_openai.go
@@ -142,7 +142,8 @@ func newEmbeddingFuncOpenAICompat(baseURL, apiKey, model string, normalized *boo
 			if *normalized {
 				return v, nil
 			}
-			return normalizeVector(v), nil
+			normalizeVectorInPlace(v)
+			return v, nil
 		}
 		checkNormalized.Do(func() {
 			if isNormalized(v) {
@@ -152,7 +153,7 @@ func newEmbeddingFuncOpenAICompat(baseURL, apiKey, model string, normalized *boo
 			}
 		})
 		if !checkedNormalized {
-			v = normalizeVector(v)
+			normalizeVectorInPlace(v)
 		}
 
 		return v, nil
diff --git a/vector.go b/vector.go
index 972b6b2..99caff9 100644
--- a/vector.go
+++ b/vector.go
@@ -19,7 +19,8 @@ func cosineSimilarity(a, b []float32) (float32, error) {
 	}
 
 	if !isNormalized(a) || !isNormalized(b) {
-		a, b = normalizeVector(a), normalizeVector(b)
+		a = normalizeVector(a)
+		b = normalizeVector(b)
 	}
 	dotProduct, err := dotProduct(a, b)
 	if err != nil {
@@ -49,19 +50,23 @@ func dotProduct(a, b []float32) (float32, error) {
 	return dotProduct, nil
 }
 
-func normalizeVector(v []float32) []float32 {
+func normalizeVectorInPlace(v []float32) {
 	var norm float32
 	for _, val := range v {
 		norm += val * val
 	}
 	norm = float32(math.Sqrt(float64(norm)))
 
-	res := make([]float32, len(v))
 	for i, val := range v {
-		res[i] = val / norm
+		v[i] = val / norm
 	}
+}
 
-	return res
+func normalizeVector(v []float32) []float32 {
+	r := make([]float32, len(v))
+	copy(r, v)
+	normalizeVectorInPlace(r)
+	return r
 }
 
 // isNormalized checks if the vector is normalized.