diff --git a/src/noise.cpp b/src/noise.cpp
index f67771b88..e68c5ce16 100644
--- a/src/noise.cpp
+++ b/src/noise.cpp
@@ -713,8 +713,7 @@ float *Noise::perlinMap2D(float x, float y, float *persistence_map)
 	if (persistence_map) {
 		if (!persist_buf)
 			persist_buf = new float[bufsize];
-		for (size_t i = 0; i != bufsize; i++)
-			persist_buf[i] = 1.0;
+		memset(persist_buf, 1.0f, sizeof(float) * bufsize);
 	}
 
 	for (size_t oct = 0; oct < np.octaves; oct++) {
@@ -751,8 +750,8 @@ float *Noise::perlinMap3D(float x, float y, float z, float *persistence_map)
 	if (persistence_map) {
 		if (!persist_buf)
 			persist_buf = new float[bufsize];
-		for (size_t i = 0; i != bufsize; i++)
-			persist_buf[i] = 1.0;
+
+		memset(persist_buf, 1.0f, sizeof(float) * bufsize);
 	}
 
 	for (size_t oct = 0; oct < np.octaves; oct++) {