Index: compiler-rt/cmake/config-ix.cmake
===================================================================
--- compiler-rt/cmake/config-ix.cmake
+++ compiler-rt/cmake/config-ix.cmake
@@ -648,10 +648,7 @@
 endif()
 
 if (COMPILER_RT_HAS_SANITIZER_COMMON AND FUZZER_SUPPORTED_ARCH AND
-    OS_NAME MATCHES "Android|Darwin|Linux|NetBSD|FreeBSD|OpenBSD|Fuchsia|Windows" AND
-    # TODO: Support builds with MSVC.
-    NOT "${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC" AND
-    NOT "${CMAKE_C_COMPILER_ID}" STREQUAL "MSVC")
+    OS_NAME MATCHES "Android|Darwin|Linux|NetBSD|FreeBSD|OpenBSD|Fuchsia|Windows")
   set(COMPILER_RT_HAS_FUZZER TRUE)
 else()
   set(COMPILER_RT_HAS_FUZZER FALSE)
Index: compiler-rt/lib/fuzzer/CMakeLists.txt
===================================================================
--- compiler-rt/lib/fuzzer/CMakeLists.txt
+++ compiler-rt/lib/fuzzer/CMakeLists.txt
@@ -71,6 +71,10 @@
 
 if(NOT HAS_THREAD_LOCAL)
   list(APPEND LIBFUZZER_CFLAGS -Dthread_local=__thread)
+  # Needed to compile with MSVC.
+  if (OS_NAME MATCHES "Windows")
+    list(APPEND LIBFUZZER_CFLAGS -D_XKEYCHECK_H=1)
+  endif()
 endif()
 
 set(FUZZER_SUPPORTED_OS ${SANITIZER_COMMON_SUPPORTED_OS})
Index: compiler-rt/lib/fuzzer/FuzzerSHA1.cpp
===================================================================
--- compiler-rt/lib/fuzzer/FuzzerSHA1.cpp
+++ compiler-rt/lib/fuzzer/FuzzerSHA1.cpp
@@ -32,7 +32,9 @@
 
 #ifdef __BIG_ENDIAN__
 # define SHA_BIG_ENDIAN
-#elif defined __LITTLE_ENDIAN__
+// Added "|| LIBFUZZER_WINDOWS" for libFuzzer to compile with MSVC since it
+// doesn't have <endian.h> and Windows is always little endian.
+#elif defined __LITTLE_ENDIAN__ || LIBFUZZER_WINDOWS
 /* override */
 #elif defined __BYTE_ORDER
 # if __BYTE_ORDER__ ==  __ORDER_BIG_ENDIAN__