diff --git a/clang-tools-extra/clang-tidy/modernize/MakeSmartPtrCheck.cpp b/clang-tools-extra/clang-tidy/modernize/MakeSmartPtrCheck.cpp
--- a/clang-tools-extra/clang-tidy/modernize/MakeSmartPtrCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/MakeSmartPtrCheck.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "../utils/TypeTraits.h"
 #include "MakeSharedCheck.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Lex/Lexer.h"
@@ -120,15 +121,20 @@
   if (New->getType()->getPointeeType()->getContainedAutoType())
     return;
 
-  // Be conservative for cases where we construct an array without any
-  // initialization.
+  // Be conservative for cases where we construct and default initialize.
+  //
   // For example,
+  //    P.reset(new int)    // check fix: P = std::make_unique<int>()
   //    P.reset(new int[5]) // check fix: P = std::make_unique<int []>(5)
   //
-  // The fix of the check has side effect, it introduces default initialization
+  // The fix of the check has side effect, it introduces value initialization
   // which maybe unexpected and cause performance regression.
-  if (New->isArray() && !New->hasInitializer())
+  const bool Initializes = New->hasInitializer() ||
+                           !utils::type_traits::isTriviallyDefaultConstructible(
+                               New->getAllocatedType(), *Result.Context);
+  if (!Initializes) {
     return;
+  }
   if (Construct)
     checkConstruct(SM, Result.Context, Construct, Type, New);
   else if (Reset)
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize-make-shared.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize-make-shared.cpp
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize-make-shared.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize-make-shared.cpp
@@ -53,14 +53,12 @@
 
   // Without parenthesis.
   std::shared_ptr<int> P2 = std::shared_ptr<int>(new int);
-  // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: use std::make_shared instead [modernize-make-shared]
-  // CHECK-FIXES: std::shared_ptr<int> P2 = std::make_shared<int>();
 
-  P2.reset(new int);
+  P2.reset(new int());
   // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use std::make_shared instead [modernize-make-shared]
   // CHECK-FIXES: P2 = std::make_shared<int>();
 
-  P2 = std::shared_ptr<int>(new int);
+  P2 = std::shared_ptr<int>(new int());
   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use std::make_shared instead [modernize-make-shared]
   // CHECK-FIXES: P2 = std::make_shared<int>();
 
@@ -69,7 +67,7 @@
   // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use std::make_shared instead
   // CHECK-FIXES: auto P3 = std::make_shared<int>();
 
-  std::shared_ptr<int> P4 = std::shared_ptr<int>((new int));
+  std::shared_ptr<int> P4 = std::shared_ptr<int>((new int()));
   // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: use std::make_shared instead [modernize-make-shared]
   // CHECK-FIXES: std::shared_ptr<int> P4 = std::make_shared<int>();
 
@@ -77,7 +75,7 @@
   // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use std::make_shared instead [modernize-make-shared]
   // CHECK-FIXES: P4 = std::make_shared<int>();
 
-  P4 = std::shared_ptr<int>(((new int)));
+  P4 = std::shared_ptr<int>(((new int())));
   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use std::make_shared instead [modernize-make-shared]
   // CHECK-FIXES: P4 = std::make_shared<int>();
 
@@ -231,13 +229,13 @@
 
 void aliases() {
   typedef std::shared_ptr<int> IntPtr;
-  IntPtr Typedef = IntPtr(new int);
+  IntPtr Typedef = IntPtr(new int());
   // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use std::make_shared instead
   // CHECK-FIXES: IntPtr Typedef = std::make_shared<int>();
 
   // We use 'bool' instead of '_Bool'.
   typedef std::shared_ptr<bool> BoolPtr;
-  BoolPtr BoolType = BoolPtr(new bool);
+  BoolPtr BoolType = BoolPtr(new bool());
   // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: use std::make_shared instead
   // CHECK-FIXES: BoolPtr BoolType = std::make_shared<bool>();
 
@@ -248,12 +246,12 @@
 // CHECK-FIXES: BasePtr StructType = std::make_shared<Base>();
 
 #define PTR shared_ptr<int>
-  std::shared_ptr<int> Macro = std::PTR(new int);
+  std::shared_ptr<int> Macro = std::PTR(new int());
 // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: use std::make_shared instead
 // CHECK-FIXES: std::shared_ptr<int> Macro = std::make_shared<int>();
 #undef PTR
 
-  std::shared_ptr<int> Using = shared_ptr_<int>(new int);
+  std::shared_ptr<int> Using = shared_ptr_<int>(new int());
   // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: use std::make_shared instead
   // CHECK-FIXES: std::shared_ptr<int> Using = std::make_shared<int>();
 }
@@ -277,7 +275,7 @@
   Nest.reset(new std::shared_ptr<int>(new int));
   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use std::make_shared instead
   // CHECK-FIXES: Nest = std::make_shared<std::shared_ptr<int>>(new int);
-  Nest->reset(new int);
+  Nest->reset(new int());
   // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use std::make_shared instead
   // CHECK-FIXES: *Nest = std::make_shared<int>();
 }
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize-make-unique.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize-make-unique.cpp
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize-make-unique.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize-make-unique.cpp
@@ -96,34 +96,28 @@
   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use std::make_unique instead [modernize-make-unique]
   // CHECK-FIXES: P1 = std::make_unique<int>();
 
-  // Without parenthesis.
+  // Without parenthesis, default initialization.
   std::unique_ptr<int> P2 = std::unique_ptr<int>(new int);
-  // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: use std::make_unique instead [modernize-make-unique]
-  // CHECK-FIXES: std::unique_ptr<int> P2 = std::make_unique<int>();
 
   P2.reset(new int);
-  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use std::make_unique instead [modernize-make-unique]
-  // CHECK-FIXES: P2 = std::make_unique<int>();
 
   P2 = std::unique_ptr<int>(new int);
-  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use std::make_unique instead [modernize-make-unique]
-  // CHECK-FIXES: P2 = std::make_unique<int>();
 
   // With auto.
   auto P3 = std::unique_ptr<int>(new int());
   // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use std::make_unique instead
   // CHECK-FIXES: auto P3 = std::make_unique<int>();
 
-  std::unique_ptr<int> P4 = std::unique_ptr<int>((new int));
+  std::unique_ptr<int> P4 = std::unique_ptr<int>((new int()));
   // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: use std::make_unique instead [modernize-make-unique]
   // CHECK-FIXES: std::unique_ptr<int> P4 = std::make_unique<int>();
-  P4.reset((new int));
+  P4.reset((new int()));
   // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use std::make_unique instead [modernize-make-unique]
   // CHECK-FIXES: P4 = std::make_unique<int>();
-  std::unique_ptr<int> P5 = std::unique_ptr<int>((((new int))));
+  std::unique_ptr<int> P5 = std::unique_ptr<int>((((new int()))));
   // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: use std::make_unique instead [modernize-make-unique]
   // CHECK-FIXES: std::unique_ptr<int> P5 = std::make_unique<int>();
-  P5.reset(((((new int)))));
+  P5.reset(((((new int())))));
   // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use std::make_unique instead [modernize-make-unique]
   // CHECK-FIXES: P5 = std::make_unique<int>();
 
@@ -137,6 +131,8 @@
     Q = unique_ptr<int>(new int());
     // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use std::make_unique instead
     // CHECK-FIXES: Q = std::make_unique<int>();
+
+    Q = unique_ptr<int>(new int);
   }
 
   std::unique_ptr<int> R(new int());
@@ -446,12 +442,12 @@
   // CHECK-FIXES: FFs = std::make_unique<Foo[]>(Num2);
 
   std::unique_ptr<int[]> FI;
-  FI.reset(new int[5]()); // default initialization.
+  FI.reset(new int[5]()); // value initialization.
   // CHECK-MESSAGES: :[[@LINE-1]]:6: warning:
   // CHECK-FIXES: FI = std::make_unique<int[]>(5);
 
   // The check doesn't give warnings and fixes for cases where the original new
-  // expression doesn't do any initialization.
+  // expression does default initialization.
   FI.reset(new int[5]);
   FI.reset(new int[Num]);
   FI.reset(new int[Num2]);
@@ -459,13 +455,13 @@
 
 void aliases() {
   typedef std::unique_ptr<int> IntPtr;
-  IntPtr Typedef = IntPtr(new int);
+  IntPtr Typedef = IntPtr(new int());
   // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use std::make_unique instead
   // CHECK-FIXES: IntPtr Typedef = std::make_unique<int>();
 
   // We use 'bool' instead of '_Bool'.
   typedef std::unique_ptr<bool> BoolPtr;
-  BoolPtr BoolType = BoolPtr(new bool);
+  BoolPtr BoolType = BoolPtr(new bool());
   // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: use std::make_unique instead
   // CHECK-FIXES: BoolPtr BoolType = std::make_unique<bool>();
 
@@ -476,12 +472,12 @@
 // CHECK-FIXES: BasePtr StructType = std::make_unique<Base>();
 
 #define PTR unique_ptr<int>
-  std::unique_ptr<int> Macro = std::PTR(new int);
+  std::unique_ptr<int> Macro = std::PTR(new int());
 // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: use std::make_unique instead
 // CHECK-FIXES: std::unique_ptr<int> Macro = std::make_unique<int>();
 #undef PTR
 
-  std::unique_ptr<int> Using = unique_ptr_<int>(new int);
+  std::unique_ptr<int> Using = unique_ptr_<int>(new int());
   // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: use std::make_unique instead
   // CHECK-FIXES: std::unique_ptr<int> Using = std::make_unique<int>();
 }
@@ -505,7 +501,7 @@
   Nest.reset(new std::unique_ptr<int>(new int));
   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use std::make_unique instead
   // CHECK-FIXES: Nest = std::make_unique<std::unique_ptr<int>>(new int);
-  Nest->reset(new int);
+  Nest->reset(new int());
   // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use std::make_unique instead
   // CHECK-FIXES: *Nest = std::make_unique<int>();
 }