Index: clang-tidy/misc/MisplacedWideningCastCheck.cpp
===================================================================
--- clang-tidy/misc/MisplacedWideningCastCheck.cpp
+++ clang-tidy/misc/MisplacedWideningCastCheck.cpp
@@ -21,7 +21,7 @@
 MisplacedWideningCastCheck::MisplacedWideningCastCheck(
     StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
-      CheckImplicitCasts(Options.get("CheckImplicitCasts", true)) {}
+      CheckImplicitCasts(Options.get("CheckImplicitCasts", false)) {}
 
 void MisplacedWideningCastCheck::storeOptions(
     ClangTidyOptions::OptionMap &Opts) {
Index: test/clang-tidy/misc-misplaced-widening-cast-implicit-enabled.cpp
===================================================================
--- /dev/null
+++ test/clang-tidy/misc-misplaced-widening-cast-implicit-enabled.cpp
@@ -0,0 +1,101 @@
+// RUN: %check_clang_tidy %s misc-misplaced-widening-cast %t -- -config="{CheckOptions: [{key: misc-misplaced-widening-cast.CheckImplicitCasts, value: 1}]}" --
+
+void func(long arg) {}
+
+void assign(int a, int b) {
+  long l;
+
+  l = a * b;
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long' is ineffective, or there is loss of precision before the conversion [misc-misplaced-widening-cast]
+  l = (long)(a * b);
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+  l = (long)a * b;
+
+  l = a << 8;
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+  l = (long)(a << 8);
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+  l = (long)b << 8;
+
+  l = static_cast<long>(a * b);
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+}
+
+void compare(int a, int b, long c) {
+  bool l;
+
+  l = a * b == c;
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+  l = c == a * b;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
+  l = (long)(a * b) == c;
+  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
+  l = c == (long)(a * b);
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
+  l = (long)a * b == c;
+  l = c == (long)a * b;
+}
+
+void init(unsigned int n) {
+  long l1 = n << 8;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: either cast from 'unsigned int' to 'long'
+  long l2 = (long)(n << 8);
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: either cast from 'unsigned int' to 'long'
+  long l3 = (long)n << 8;
+}
+
+void call(unsigned int n) {
+  func(n << 8);
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: either cast from 'unsigned int' to 'long'
+  func((long)(n << 8));
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: either cast from 'unsigned int' to 'long'
+  func((long)n << 8);
+}
+
+long ret(int a) {
+  if (a < 0) {
+    return a * 1000;
+    // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
+  } else if (a > 0) {
+    return (long)(a * 1000);
+    // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
+  } else {
+    return (long)a * 1000;
+  }
+}
+
+void dontwarn1(unsigned char a, int i, unsigned char *p) {
+  long l;
+  // The result is a 9 bit value, there is no truncation in the implicit cast.
+  l = (long)(a + 15);
+  // The result is a 12 bit value, there is no truncation in the implicit cast.
+  l = (long)(a << 4);
+  // The result is a 3 bit value, there is no truncation in the implicit cast.
+  l = (long)((i % 5) + 1);
+  // The result is a 16 bit value, there is no truncation in the implicit cast.
+  l = (long)(((*p) << 8) + *(p + 1));
+}
+
+template <class T> struct DontWarn2 {
+  void assign(T a, T b) {
+    long l;
+    l = (long)(a * b);
+  }
+};
+DontWarn2<int> DW2;
+
+// Cast is not suspicious when casting macro.
+#define A  (X<<2)
+long macro1(int X) {
+  return (long)A;
+}
+
+// Don't warn about cast in macro.
+#define B(X,Y)   (long)(X*Y)
+long macro2(int x, int y) {
+  return B(x,y);
+}
+
+void floatingpoint(float a, float b) {
+  double d = (double)(a * b); // Currently we don't warn for this.
+}
Index: test/clang-tidy/misc-misplaced-widening-cast.cpp
===================================================================
--- test/clang-tidy/misc-misplaced-widening-cast.cpp
+++ /dev/null
@@ -1,101 +0,0 @@
-// RUN: %check_clang_tidy %s misc-misplaced-widening-cast %t -- -config="{CheckOptions: [{key: misc-misplaced-widening-cast.CheckImplicitCasts, value: 1}]}" --
-
-void func(long arg) {}
-
-void assign(int a, int b) {
-  long l;
-
-  l = a * b;
-  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long' is ineffective, or there is loss of precision before the conversion [misc-misplaced-widening-cast]
-  l = (long)(a * b);
-  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
-  l = (long)a * b;
-
-  l = a << 8;
-  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
-  l = (long)(a << 8);
-  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
-  l = (long)b << 8;
-
-  l = static_cast<long>(a * b);
-  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
-}
-
-void compare(int a, int b, long c) {
-  bool l;
-
-  l = a * b == c;
-  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
-  l = c == a * b;
-  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
-  l = (long)(a * b) == c;
-  // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: either cast from 'int' to 'long'
-  l = c == (long)(a * b);
-  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
-  l = (long)a * b == c;
-  l = c == (long)a * b;
-}
-
-void init(unsigned int n) {
-  long l1 = n << 8;
-  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: either cast from 'unsigned int' to 'long'
-  long l2 = (long)(n << 8);
-  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: either cast from 'unsigned int' to 'long'
-  long l3 = (long)n << 8;
-}
-
-void call(unsigned int n) {
-  func(n << 8);
-  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: either cast from 'unsigned int' to 'long'
-  func((long)(n << 8));
-  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: either cast from 'unsigned int' to 'long'
-  func((long)n << 8);
-}
-
-long ret(int a) {
-  if (a < 0) {
-    return a * 1000;
-    // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
-  } else if (a > 0) {
-    return (long)(a * 1000);
-    // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
-  } else {
-    return (long)a * 1000;
-  }
-}
-
-void dontwarn1(unsigned char a, int i, unsigned char *p) {
-  long l;
-  // The result is a 9 bit value, there is no truncation in the implicit cast.
-  l = (long)(a + 15);
-  // The result is a 12 bit value, there is no truncation in the implicit cast.
-  l = (long)(a << 4);
-  // The result is a 3 bit value, there is no truncation in the implicit cast.
-  l = (long)((i % 5) + 1);
-  // The result is a 16 bit value, there is no truncation in the implicit cast.
-  l = (long)(((*p) << 8) + *(p + 1));
-}
-
-template <class T> struct DontWarn2 {
-  void assign(T a, T b) {
-    long l;
-    l = (long)(a * b);
-  }
-};
-DontWarn2<int> DW2;
-
-// Cast is not suspicious when casting macro.
-#define A  (X<<2)
-long macro1(int X) {
-  return (long)A;
-}
-
-// Don't warn about cast in macro.
-#define B(X,Y)   (long)(X*Y)
-long macro2(int x, int y) {
-  return B(x,y);
-}
-
-void floatingpoint(float a, float b) {
-  double d = (double)(a * b); // Currently we don't warn for this.
-}