diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -1480,22 +1480,6 @@
       Targets[I.index()] = Env;
   }
 
-  // Do not allow conflicts with the watchOS target.
-  if (!Targets[Darwin::WatchOS].empty() &&
-      (!Targets[Darwin::IPhoneOS].empty() || !Targets[Darwin::TvOS].empty())) {
-    TheDriver.Diag(diag::err_drv_conflicting_deployment_targets)
-        << "WATCHOS_DEPLOYMENT_TARGET"
-        << (!Targets[Darwin::IPhoneOS].empty() ? "IPHONEOS_DEPLOYMENT_TARGET"
-                                               : "TVOS_DEPLOYMENT_TARGET");
-  }
-
-  // Do not allow conflicts with the tvOS target.
-  if (!Targets[Darwin::TvOS].empty() && !Targets[Darwin::IPhoneOS].empty()) {
-    TheDriver.Diag(diag::err_drv_conflicting_deployment_targets)
-        << "TVOS_DEPLOYMENT_TARGET"
-        << "IPHONEOS_DEPLOYMENT_TARGET";
-  }
-
   // Allow conflicts among OSX and iOS for historical reasons, but choose the
   // default platform.
   if (!Targets[Darwin::MacOS].empty() &&
@@ -1508,6 +1492,18 @@
     else
       Targets[Darwin::IPhoneOS] = Targets[Darwin::WatchOS] =
           Targets[Darwin::TvOS] = "";
+  } else {
+    // Don't allow conflicts in any other platform.
+    int FirstTarget = llvm::array_lengthof(Targets);
+    for (int I = 0; I != llvm::array_lengthof(Targets); ++I) {
+      if (Targets[I].empty())
+        continue;
+      if (FirstTarget == llvm::array_lengthof(Targets))
+        FirstTarget = I;
+      else
+        TheDriver.Diag(diag::err_drv_conflicting_deployment_targets)
+            << Targets[FirstTarget] << Targets[I];
+    }
   }
 
   for (const auto &Target : llvm::enumerate(llvm::makeArrayRef(Targets))) {