diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index e6c6584efbc8..71e05b932b88 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1603,11 +1603,11 @@ def mpure_code : Flag<["-"], "mpure-code">, Alias<mexecute_only>; // Alias for G
 def mno_pure_code : Flag<["-"], "mno-pure-code">, Alias<mno_execute_only>;
 def mtvos_version_min_EQ : Joined<["-"], "mtvos-version-min=">, Group<m_Group>;
 def mappletvos_version_min_EQ : Joined<["-"], "mappletvos-version-min=">, Alias<mtvos_version_min_EQ>;
-def mtvos_simulator_version_min_EQ : Joined<["-"], "mtvos-simulator-version-min=">, Alias<mtvos_version_min_EQ>;
-def mappletvsimulator_version_min_EQ : Joined<["-"], "mappletvsimulator-version-min=">, Alias<mtvos_version_min_EQ>;
+def mtvos_simulator_version_min_EQ : Joined<["-"], "mtvos-simulator-version-min=">;
+def mappletvsimulator_version_min_EQ : Joined<["-"], "mappletvsimulator-version-min=">, Alias<mtvos_simulator_version_min_EQ>;
 def mwatchos_version_min_EQ : Joined<["-"], "mwatchos-version-min=">, Group<m_Group>;
-def mwatchos_simulator_version_min_EQ : Joined<["-"], "mwatchos-simulator-version-min=">, Alias<mwatchos_version_min_EQ>;
-def mwatchsimulator_version_min_EQ : Joined<["-"], "mwatchsimulator-version-min=">, Alias<mwatchos_version_min_EQ>;
+def mwatchos_simulator_version_min_EQ : Joined<["-"], "mwatchos-simulator-version-min=">;
+def mwatchsimulator_version_min_EQ : Joined<["-"], "mwatchsimulator-version-min=">, Alias<mwatchos_simulator_version_min_EQ>;
 def march_EQ : Joined<["-"], "march=">, Group<m_Group>;
 def masm_EQ : Joined<["-"], "masm=">, Group<m_Group>, Flags<[DriverOption]>;
 def mcmodel_EQ : Joined<["-"], "mcmodel=">, Group<m_Group>;
@@ -1636,8 +1636,8 @@ def mhard_float : Flag<["-"], "mhard-float">, Group<m_Group>;
 def miphoneos_version_min_EQ : Joined<["-"], "miphoneos-version-min=">, Group<m_Group>;
 def mios_version_min_EQ : Joined<["-"], "mios-version-min=">,
   Alias<miphoneos_version_min_EQ>, HelpText<"Set iOS deployment target">;
-def mios_simulator_version_min_EQ : Joined<["-"], "mios-simulator-version-min=">, Alias<miphoneos_version_min_EQ>;
-def miphonesimulator_version_min_EQ : Joined<["-"], "miphonesimulator-version-min=">, Alias<miphoneos_version_min_EQ>;
+def mios_simulator_version_min_EQ : Joined<["-"], "mios-simulator-version-min=">;
+def miphonesimulator_version_min_EQ : Joined<["-"], "miphonesimulator-version-min=">, Alias<mios_simulator_version_min_EQ>;
 def mkernel : Flag<["-"], "mkernel">, Group<m_Group>;
 def mlinker_version_EQ : Joined<["-"], "mlinker-version=">,
   Flags<[DriverOption]>;
diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
index 4cddf65c6c9d..6952f4551672 100644
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -1125,9 +1125,22 @@ void Darwin::AddDeploymentTarget(DerivedArgList &Args) const {
   }
 
   Arg *OSXVersion = Args.getLastArg(options::OPT_mmacosx_version_min_EQ);
-  Arg *iOSVersion = Args.getLastArg(options::OPT_miphoneos_version_min_EQ);
-  Arg *TvOSVersion = Args.getLastArg(options::OPT_mtvos_version_min_EQ);
-  Arg *WatchOSVersion = Args.getLastArg(options::OPT_mwatchos_version_min_EQ);
+  Arg *iOSVersion = Args.getLastArg(options::OPT_miphoneos_version_min_EQ,
+                                    options::OPT_mios_simulator_version_min_EQ);
+  Arg *TvOSVersion =
+      Args.getLastArg(options::OPT_mtvos_version_min_EQ,
+                      options::OPT_mtvos_simulator_version_min_EQ);
+  Arg *WatchOSVersion =
+      Args.getLastArg(options::OPT_mwatchos_version_min_EQ,
+                      options::OPT_mwatchos_simulator_version_min_EQ);
+
+  // Add a macro to differentiate between m(iphone|tv|watch)os-version-min=X.Y and
+  // -m(iphone|tv|watch)simulator-version-min=X.Y.
+  if (Args.hasArg(options::OPT_mios_simulator_version_min_EQ) ||
+      Args.hasArg(options::OPT_mtvos_simulator_version_min_EQ) ||
+      Args.hasArg(options::OPT_mwatchos_simulator_version_min_EQ))
+    Args.append(Args.MakeSeparateArg(nullptr, Opts.getOption(options::OPT_D),
+                                     " __APPLE_EMBEDDED_SIMULATOR__=1"));
 
   if (OSXVersion && (iOSVersion || TvOSVersion || WatchOSVersion)) {
     getDriver().Diag(diag::err_drv_argument_not_allowed_with)
diff --git a/clang/test/Driver/darwin-simulator-macro.c b/clang/test/Driver/darwin-simulator-macro.c
new file mode 100644
index 000000000000..6971e9303a6d
--- /dev/null
+++ b/clang/test/Driver/darwin-simulator-macro.c
@@ -0,0 +1,12 @@
+// RUN: %clang -target x86_64-apple-darwin10 -arch x86_64 -mios-simulator-version-min=6.0.0 -E -dM %s | FileCheck -check-prefix=SIM %s
+// RUN: %clang -target x86_64-apple-darwin10 -arch x86_64 -miphonesimulator-version-min=6.0.0 -E -dM %s | FileCheck -check-prefix=SIM %s
+// RUN: %clang -target x86_64-apple-darwin10 -arch x86_64 -mtvos-simulator-version-min=6.0.0 -E -dM %s | FileCheck -check-prefix=SIM %s
+// RUN: %clang -target x86_64-apple-darwin10 -arch x86_64 -mappletvsimulator-version-min=6.0.0 -E -dM %s | FileCheck -check-prefix=SIM %s
+// RUN: %clang -target x86_64-apple-darwin10 -arch x86_64 -mwatchos-simulator-version-min=6.0.0 -E -dM %s | FileCheck -check-prefix=SIM %s
+// RUN: %clang -target x86_64-apple-darwin10 -arch x86_64 -mwatchsimulator-version-min=6.0.0 -E -dM %s | FileCheck -check-prefix=SIM %s
+// RUN: %clang -target x86_64-apple-darwin10 -arch x86_64 -mios-version-min=6.0.0 -E -dM %s | FileCheck -check-prefix=DEV %s
+// RUN: %clang -target x86_64-apple-darwin10 -arch x86_64 -mtvos-version-min=6.0.0 -E -dM %s | FileCheck -check-prefix=DEV %s
+// RUN: %clang -target x86_64-apple-darwin10 -arch x86_64 -mwatchos-version-min=6.0.0 -E -dM %s | FileCheck -check-prefix=DEV %s
+
+// SIM: #define __APPLE_EMBEDDED_SIMULATOR__ 1
+// DEV-NOT: __APPLE_EMBEDDED_SIMULATOR__