diff --git a/configure.in b/configure.in
index ab0cea9905..923843fe6f 100644
--- a/configure.in
+++ b/configure.in
@@ -1009,6 +1009,7 @@ main()
 		ac_cv_type_struct_timeval=yes
                 ac_cv_func_clock_gettime=yes
                 ac_cv_func_clock_getres=yes
+		ac_cv_func_malloc_usable_size=no
 		AC_CHECK_TYPE([NET_LUID], [], [],
 			      [@%:@include <windows.h>
 		  	      @%:@include <iphlpapi.h>])
diff --git a/gc.c b/gc.c
index c15b19c44f..9963cdec52 100644
--- a/gc.c
+++ b/gc.c
@@ -35,6 +35,12 @@
 # define __has_feature(x) 0
 #endif
 
+#ifndef HAVE_MALLOC_USABLE_SIZE
+# ifdef _WIN32
+#   define malloc_usable_size(a) _msize(a)
+# endif
+#endif
+
 #if /* is ASAN enabled? */ \
     __has_feature(address_sanitizer) /* Clang */ || \
     defined(__SANITIZE_ADDRESS__)  /* GCC 4.8.x */