diff --git a/compiler-rt/lib/asan/CMakeLists.txt b/compiler-rt/lib/asan/CMakeLists.txt
index b23a7a2e5abd..69c0cd8c2636 100644
--- a/compiler-rt/lib/asan/CMakeLists.txt
+++ b/compiler-rt/lib/asan/CMakeLists.txt
@@ -179,7 +179,7 @@ else()
       add_compiler_rt_runtime(clang_rt.asan_dll_thunk-${arch} ${arch} STATIC
         SOURCES asan_dll_thunk.cc
                 $<TARGET_OBJECTS:RTInterception.${arch}>
-        CFLAGS ${ASAN_CFLAGS} -DASAN_DLL_THUNK
+        CFLAGS ${ASAN_CFLAGS} -DASAN_DLL_THUNK -DSANITIZER_DLL_THUNK
         DEFS ${ASAN_COMMON_DEFINITIONS})
       add_dependencies(asan clang_rt.asan_dll_thunk-${arch})
     endif()
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h b/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h
index c8985b49eb8c..8832da069098 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h
@@ -17,7 +17,11 @@
 
 // Only use SANITIZER_*ATTRIBUTE* before the function return type!
 #if SANITIZER_WINDOWS
-# define SANITIZER_INTERFACE_ATTRIBUTE __declspec(dllexport)
+# if defined(SANITIZER_DLL_THUNK)
+#  define SANITIZER_INTERFACE_ATTRIBUTE
+# else
+#  define SANITIZER_INTERFACE_ATTRIBUTE __declspec(dllexport)
+# endif
 // FIXME find out what we need on Windows, if anything.
 # define SANITIZER_WEAK_ATTRIBUTE
 #elif defined(SANITIZER_GO)