diff --git a/xmalloc.c b/xmalloc.c
index 28af50f9..9e305061 100644
--- a/xmalloc.c
+++ b/xmalloc.c
@@ -71,7 +71,7 @@ xvasprintf_(char **strp, const char *format, va_list ap)
     return vsnprintf(*strp, n + 1, format, ap);
 }
 
-static VPRINTF(1) char *
+char *
 xvasprintf(const char *format, va_list ap)
 {
     char *str;
diff --git a/xmalloc.h b/xmalloc.h
index 13d69ca4..bc0dd2d8 100644
--- a/xmalloc.h
+++ b/xmalloc.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <stdarg.h>
 #include <stddef.h>
 #include <wchar.h>
 #include "macros.h"
@@ -10,4 +11,5 @@ void *xrealloc(void *ptr, size_t size);
 char *xstrdup(const char *str) XSTRDUP;
 char *xstrndup(const char *str, size_t n) XSTRDUP;
 char *xasprintf(const char *format, ...) PRINTF(1) XMALLOC;
+char *xvasprintf(const char *format, va_list va) VPRINTF(1) XMALLOC;
 wchar_t *xwcsdup(const wchar_t *str) XSTRDUP;