diff --git a/llvm/lib/Target/TargetLibraryInfo.cpp b/llvm/lib/Target/TargetLibraryInfo.cpp
index 6ff7441bbd33..616ff9067300 100644
--- a/llvm/lib/Target/TargetLibraryInfo.cpp
+++ b/llvm/lib/Target/TargetLibraryInfo.cpp
@@ -426,7 +426,7 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T,
     TLI.setUnavailable(LibFunc::fiprintf);
   }
 
-  if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
+  if (T.isOSWindows() && !T.isOSCygMing()) {
     // Win32 does not support long double
     TLI.setUnavailable(LibFunc::acosl);
     TLI.setUnavailable(LibFunc::asinl);