diff --git a/lib/dropin.c b/lib/dropin.c
index a3c28b04..23d2b136 100644
--- a/lib/dropin.c
+++ b/lib/dropin.c
@@ -125,27 +125,36 @@ char *get_current_dir_name(void)
 #endif
 
 #ifndef HAVE_ASPRINTF
-int asprintf(char **buf, const char *fmt, ...)
+int asprintf(char **buf, const char *fmt, ...) {
+	int result;
+	va_list ap;
+	va_start(ap, fmt);
+	result = vasprintf(buf, fmt, ap);
+	va_end(ap);
+	return result;
+}
+
+int vasprintf(char **buf, const char *fmt, va_list ap) {
 {
 	int status;
-	va_list ap;
+	va_list aq;
 	int len;
 
 	len = 4096;
 	*buf = xmalloc(len);
 
-	va_start(ap, fmt);
-	status = vsnprintf(*buf, len, fmt, ap);
-	va_end(ap);
+	va_copy(aq, ap);
+	status = vsnprintf(*buf, len, fmt, aq);
+	va_end(aq);
 
 	if(status >= 0)
 		*buf = xrealloc(*buf, status + 1);
 
 	if(status > len - 1) {
 		len = status;
-		va_start(ap, fmt);
-		status = vsnprintf(*buf, len, fmt, ap);
-		va_end(ap);
+		va_copy(aq, ap);
+		status = vsnprintf(*buf, len, fmt, aq);
+		va_end(aq);
 	}
 
 	return status;
diff --git a/lib/dropin.h b/lib/dropin.h
index eabc4c4d..72109c84 100644
--- a/lib/dropin.h
+++ b/lib/dropin.h
@@ -36,6 +36,7 @@ extern char *get_current_dir_name(void);
 
 #ifndef HAVE_ASPRINTF
 extern int asprintf(char **, const char *, ...);
+extern int vasprintf(char **, const char *, va_list ap);
 #endif
 
 #ifndef HAVE_GETNAMEINFO
diff --git a/lib/xalloc.h b/lib/xalloc.h
index 7cb486a2..51f99bdf 100644
--- a/lib/xalloc.h
+++ b/lib/xalloc.h
@@ -24,3 +24,6 @@ void *xcalloc PARAMS ((size_t n, size_t s));
 void *xrealloc PARAMS ((void *p, size_t n)) __attribute__ ((__malloc__));
 
 char *xstrdup PARAMS ((const char *s)) __attribute__ ((__malloc__));
+
+extern int xasprintf(char **strp, const char *fmt, ...);
+extern int xvasprintf(char **strp, const char *fmt, va_list ap);
diff --git a/lib/xmalloc.c b/lib/xmalloc.c
index d02f41b9..51356e46 100644
--- a/lib/xmalloc.c
+++ b/lib/xmalloc.c
@@ -22,6 +22,8 @@
 #include <sys/types.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdarg.h>
+#include <errno.h>
 
 #if STDC_HEADERS
 # include <stdlib.h>
@@ -138,3 +140,21 @@ xcalloc (n, s)
 }
 
 #endif /* NOT_USED */
+
+int xasprintf(char **strp, const char *fmt, ...) {
+	int result;
+	va_list ap;
+	va_start(ap, fmt);
+	result = xvasprintf(strp, fmt, ap);
+	va_end(ap);
+	return result;
+}
+
+int xvasprintf(char **strp, const char *fmt, va_list ap) {
+	int result = vasprintf(strp, fmt, ap);
+	if(result < 0) {
+		fprintf(stderr, "vasprintf() failed: %s\n", strerror(errno));
+  		exit(xalloc_exit_failure);
+	}
+	return result;
+}