diff --git a/configure.ac b/configure.ac
index 5c79f3cfd3..a106e1eedd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -440,7 +440,8 @@ if test "x${COMPILE_JNI}" = xyes; then
   AC_EGREP_HEADER(u_int32_t, sys/config.h, AC_DEFINE(HAVE_BSD_INT32_DEFINED, 1, [Define to 1 if you have BSD u_int32_t]))
 
   AC_SEARCH_LIBS([clock_gettime], [rt])
-  AC_SEARCH_LIBS([inet_pton],[nsl])
+  dnl Haiku has the socket functions and h_errno in libnetwork.
+  AC_SEARCH_LIBS([inet_pton],[nsl network])
   AC_CHECK_LIB([socket], [gethostname]) 
 
   AC_CHECK_FUNCS([ftruncate fsync select \
diff --git a/native/jni/java-net/java_net_VMNetworkInterface.c b/native/jni/java-net/java_net_VMNetworkInterface.c
index 658299733e..90da75857c 100644
--- a/native/jni/java-net/java_net_VMNetworkInterface.c
+++ b/native/jni/java-net/java_net_VMNetworkInterface.c
@@ -51,6 +51,11 @@ exception statement from your version. */
 #include <string.h>
 
 #include <net/if.h>
+
+/* Haiku does not define IFF_RUNNING. */
+#ifndef IFF_RUNNING
+#define IFF_RUNNING 0x40
+#endif
 #include <sys/ioctl.h>
 /* Required on Solaris. */
 #include <unistd.h>
diff --git a/native/jni/native-lib/cpnet.c b/native/jni/native-lib/cpnet.c
index 534eaa46ed..eeced7d6a2 100644
--- a/native/jni/native-lib/cpnet.c
+++ b/native/jni/native-lib/cpnet.c
@@ -645,7 +645,12 @@ jint cpnet_getHostByName (JNIEnv *env, const char *hostname, cpnet_address ***ad
     {
       buf = (char *)JCL_malloc(env, buflen);
 
-#ifdef HAVE_GETHOSTBYNAME_R
+/* Use gethostbyname_r only if its declaration was found.  Haiku has the
+   function in libnetwork but does not declare it. */
+#if defined(HAVE_GETHOSTBYNAME_R) \
+    && (defined(HAVE_FUNC_GETHOSTBYNAME_R_6) \
+        || defined(HAVE_FUNC_GETHOSTBYNAME_R_5) \
+        || defined(HAVE_FUNC_GETHOSTBYNAME_R_3))
 # if defined(HAVE_FUNC_GETHOSTBYNAME_R_6)
       ret = gethostbyname_r (hostname, &hret, buf, buflen, &result, &herr);
 # elif defined(HAVE_FUNC_GETHOSTBYNAME_R_5)