diff --git a/lib/Target/TargetLibraryInfo.cpp b/lib/Target/TargetLibraryInfo.cpp
index 6ec0b1f929c..6ff7441bbd3 100644
--- a/lib/Target/TargetLibraryInfo.cpp
+++ b/lib/Target/TargetLibraryInfo.cpp
@@ -426,7 +426,7 @@ static void initialize(TargetLibraryInfo &TLI, const Triple &T,
     TLI.setUnavailable(LibFunc::fiprintf);
   }
 
-  if (T.isKnownWindowsMSVCEnvironment()) {
+  if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
     // Win32 does not support long double
     TLI.setUnavailable(LibFunc::acosl);
     TLI.setUnavailable(LibFunc::asinl);
diff --git a/test/MC/X86/x86-windows-itanium-libcalls.ll b/test/MC/X86/x86-windows-itanium-libcalls.ll
new file mode 100644
index 00000000000..773d03b4def
--- /dev/null
+++ b/test/MC/X86/x86-windows-itanium-libcalls.ll
@@ -0,0 +1,16 @@
+; RUN: opt -mtriple i686-windows-itanium -O2 -o - %s | llvm-dis | FileCheck %s
+
+target triple = "i686-windows-itanium"
+
+declare dllimport double @floor(double)
+
+define dllexport float @test(float %f) {
+  %conv = fpext float %f to double
+  %call = tail call double @floor(double %conv)
+  %cast = fptrunc double %call to float
+  ret float %cast
+}
+
+; CHECK-NOT: floorf
+; CHECK: floor
+