diff --git a/common/common-config.win.h b/common/common-config.win.h
index b984fb4..2f84e9c 100644
--- a/common/common-config.win.h
+++ b/common/common-config.win.h
@@ -1,7 +1,11 @@
 /* common-config.win.h - Platform-specific definitions for Windows */
 
 #define HAVE_VSNPRINTF 1
+#ifdef _MSC_VER
+/* Older versions of MSVC lacks vsnprintf. MinGW has it, and if this
+   macro is defined before stdio.h is included, things will break. */
 #define vsnprintf _vsnprintf
+#endif
 
 #define HAVE_SNPRINTF 1
 #define snprintf _snprintf