diff --git a/Misc/NEWS b/Misc/NEWS
index 3f49d9c9ac1..f1db374a540 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -664,6 +664,9 @@ IDLE
 Build
 -----
 
+- Issue #21958: Define HAVE_ROUND when building with Visual Studio 2013 and
+  above.  Patch by Zachary Turner.
+
 - Issue #18093: the programs that embed the CPython runtime are now in a
   separate "Programs" directory, rather than being kept in the Modules
   directory.
diff --git a/PC/pyconfig.h b/PC/pyconfig.h
index e82e6e9047a..49c25997b5a 100644
--- a/PC/pyconfig.h
+++ b/PC/pyconfig.h
@@ -436,6 +436,11 @@ Py_NO_ENABLE_SHARED to find out.  Also support MS_NO_COREDLL for b/w compat */
 /* Define to 1 if you have the `copysign' function. */
 #define HAVE_COPYSIGN 1
 
+/* Define to 1 if you have the `round' function. */
+#if _MSC_VER >= 1800
+#define HAVE_ROUND 1
+#endif
+
 /* Define to 1 if you have the `isinf' macro. */
 #define HAVE_DECL_ISINF 1