diff --git a/base/HidlInternal.cpp b/base/HidlInternal.cpp
index babdac1..7d7e960 100644
--- a/base/HidlInternal.cpp
+++ b/base/HidlInternal.cpp
@@ -153,7 +153,7 @@
 
     for (const auto& path : instrumentationLibPaths) {
         DIR *dir = opendir(path.c_str());
-        if (dir == 0) {
+        if (dir == nullptr) {
             LOG(WARNING) << path << " does not exist. ";
             return;
         }
diff --git a/libhidlcache/MemoryDealer.cpp b/libhidlcache/MemoryDealer.cpp
index e9196a1..dea7bc7 100644
--- a/libhidlcache/MemoryDealer.cpp
+++ b/libhidlcache/MemoryDealer.cpp
@@ -240,7 +240,7 @@
             return freed;
         }
     }
-    return 0;
+    return nullptr;
 }
 
 void SimpleBestFitAllocator::dump(const char* tag) const {
diff --git a/minijail/HardwareMinijail.cpp b/minijail/HardwareMinijail.cpp
index e6b1144..990a689 100644
--- a/minijail/HardwareMinijail.cpp
+++ b/minijail/HardwareMinijail.cpp
@@ -29,7 +29,7 @@
     }
 
     struct minijail* jail = minijail_new();
-    if (jail == NULL) {
+    if (jail == nullptr) {
         LOG(FATAL) << "Failed to create minijail.";
     }