diff --git a/utils/hwcutils.cpp b/utils/hwcutils.cpp
index 322efce..9a49c41 100644
--- a/utils/hwcutils.cpp
+++ b/utils/hwcutils.cpp
@@ -30,18 +30,18 @@
 namespace android {
 
 const hwc_drm_bo *DrmHwcBuffer::operator->() const {
-  if (importer_ == NULL) {
+  if (importer_ == nullptr) {
     ALOGE("Access of non-existent BO");
     exit(1);
-    return NULL;
+    return nullptr;
   }
   return &bo_;
 }
 
 void DrmHwcBuffer::Clear() {
-  if (importer_ != NULL) {
+  if (importer_ != nullptr) {
     importer_->ReleaseBuffer(&bo_);
-    importer_ = NULL;
+    importer_ = nullptr;
   }
 }
 
@@ -60,7 +60,7 @@
     return ret;
   }
 
-  if (importer_ != NULL) {
+  if (importer_ != nullptr) {
     importer_->ReleaseBuffer(&bo_);
   }
 
@@ -97,13 +97,13 @@
 }
 
 void DrmHwcNativeHandle::Clear() {
-  if (handle_ != NULL) {
+  if (handle_ != nullptr) {
     GraphicBufferMapper &gm(GraphicBufferMapper::get());
     int ret = gm.freeBuffer(handle_);
     if (ret) {
       ALOGE("Failed to free buffer handle %d", ret);
     }
-    handle_ = NULL;
+    handle_ = nullptr;
   }
 }