Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -32,11 +32,13 @@
 	have_sel_getName="yes"
 	AC_DEFINE(HAVE_SEL_GETNAME, 1, [Whether we have sel_getName])])
 test x"$have_sel_get_name" != x"yes" -a x"$have_sel_getName" != x"yes" && \
 	AC_ERROR(You need either sel_get_name or sel_getName in libobjc!)
 
-AC_CHECK_FUNC(asprintf, AC_DEFINE(HAVE_ASPRINTF, 1, "Whether we have asprintf"))
+AC_CHECK_FUNC(asprintf, [
+	AC_DEFINE(HAVE_ASPRINTF, 1, "Whether we have asprintf")
+	AC_SUBST(ASPRINTF, "asprintf.c")])
 
 AC_MSG_CHECKING(whether we have IPv6 support)
 AC_TRY_RUN([
 	#include <stdlib.h>
 	#include <string.h>

Index: extra.mk.in
==================================================================
--- extra.mk.in
+++ extra.mk.in
@@ -1,1 +1,2 @@
+ASPRINTF = @ASPRINTF@
 TESTS = @TESTS@

Index: src/Makefile
==================================================================
--- src/Makefile
+++ src/Makefile
@@ -1,5 +1,7 @@
+include ../extra.mk
+
 LIB = ${LIB_PREFIX}objfw${LIB_SUFFIX}
 LIB_MAJOR = 1
 LIB_MINOR = 0
 
 SRCS = OFArray.m		\
@@ -10,11 +12,11 @@
        OFListObject.m		\
        OFObject.m		\
        OFString.m		\
        OFTCPSocket.m		\
        OFXMLFactory.m		\
-       asprintf.c
+       ${ASPRINTF}
 
 INCLUDES = ${SRCS:.m=.h}	\
 	   OFMacros.h		\
 	   OFStream.h
 

Index: src/asprintf.c
==================================================================
--- src/asprintf.c
+++ src/asprintf.c
@@ -9,11 +9,10 @@
  * the packaging of this file.
  */
 
 #include "config.h"
 
-#ifndef HAVE_ASPRINTF
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 
 int
@@ -29,6 +28,5 @@
 	if ((*strp = malloc((size_t)size + 1)) == NULL)
 		return -1;
 
 	return vsnprintf(*strp, (size_t)size + 1, fmt, args);
 }
-#endif