diff --git a/configure.ac b/configure.ac
index 5490cf02..dc083bb6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -686,6 +686,8 @@ AC_CHECK_HEADERS(ws2tcpip.h)
 
 AC_CHECK_HEADERS(wspiapi.h)
 
+AC_CHECK_HEADERS(alloca.h)
+
 # Add -D_POSIX_PTHREAD_SEMANTICS if on Solaris
 #
 case $host_os in
diff --git a/dbus/dbus-sysdeps-unix.c b/dbus/dbus-sysdeps-unix.c
index b4ecc96e..fc677990 100644
--- a/dbus/dbus-sysdeps-unix.c
+++ b/dbus/dbus-sysdeps-unix.c
@@ -71,6 +71,9 @@
 #ifdef HAVE_GETPEERUCRED
 #include <ucred.h>
 #endif
+#ifdef HAVE_ALLOCA_H
+#include <alloca.h>
+#endif
 
 #ifdef HAVE_ADT
 #include <bsm/adt.h>