diff --git a/libc/utils/FPUtil/PlatformDefs.h b/libc/utils/FPUtil/PlatformDefs.h
--- a/libc/utils/FPUtil/PlatformDefs.h
+++ b/libc/utils/FPUtil/PlatformDefs.h
@@ -13,7 +13,7 @@
 #define X87_FPU
 #endif
 
-#if defined(_WIN32) || defined(_WIN64)
+#if defined(_WIN32)
 #define LONG_DOUBLE_IS_DOUBLE
 #endif
 
diff --git a/libc/utils/FPUtil/TestHelpers.cpp b/libc/utils/FPUtil/TestHelpers.cpp
--- a/libc/utils/FPUtil/TestHelpers.cpp
+++ b/libc/utils/FPUtil/TestHelpers.cpp
@@ -74,7 +74,7 @@
 template void describeValue<long double>(const char *, long double,
                                          testutils::StreamWrapper &);
 
-#if defined(_WIN32) || defined(_WIN64)
+#if defined(_WIN32)
 #define sigjmp_buf jmp_buf
 #define sigsetjmp(buf, save) setjmp(buf)
 #define siglongjmp(buf, val) longjmp(buf, val)
diff --git a/libc/utils/UnitTest/PlatformDefs.h b/libc/utils/UnitTest/PlatformDefs.h
--- a/libc/utils/UnitTest/PlatformDefs.h
+++ b/libc/utils/UnitTest/PlatformDefs.h
@@ -9,7 +9,7 @@
 #ifndef LLVM_LIBC_UTILS_UNITTEST_PLATFORMDEFS_H
 #define LLVM_LIBC_UTILS_UNITTEST_PLATFORMDEFS_H
 
-#if !(defined(_WIN32) || defined(_WIN64))
+#if !defined(_WIN32)
 #define ENABLE_SUBPROCESS_TESTS
 #endif