diff --git a/src/kits/network/libnet/compat.c b/src/kits/network/libnet/compat.c
index 3040fe81fe..6a51d857bb 100644
--- a/src/kits/network/libnet/compat.c
+++ b/src/kits/network/libnet/compat.c
@@ -13,6 +13,8 @@
 
 #include <TLS.h>
 
+#undef h_errno
+	// was defined by netdb.h
 static int32 h_errno_tls;
 
 /* These should probably be moved to a seperate file as they
diff --git a/src/kits/network/libnet/getaddrinfo.c b/src/kits/network/libnet/getaddrinfo.c
index 103471b93d..1e01ba4a26 100644
--- a/src/kits/network/libnet/getaddrinfo.c
+++ b/src/kits/network/libnet/getaddrinfo.c
@@ -96,6 +96,9 @@
  */
 #include <stdarg.h>
 
+#undef h_errno
+	// was defined by netdb.h
+
 #ifdef YP
 #include <rpc/rpc.h>
 #include <rpcsvc/yp.h>
diff --git a/src/kits/network/libnet/getnameinfo.c b/src/kits/network/libnet/getnameinfo.c
index a082b39fb1..52abcb1bd9 100644
--- a/src/kits/network/libnet/getnameinfo.c
+++ b/src/kits/network/libnet/getnameinfo.c
@@ -52,6 +52,9 @@
 #include <string.h>
 #include <stddef.h>
 
+#undef h_errno
+	// was defined by netdb.h
+
 static const struct afd {
 	int a_af;
 	int a_addrlen;
diff --git a/src/kits/network/libnet/getnetnamadr.c b/src/kits/network/libnet/getnetnamadr.c
index 1231ed7fbd..e53c020d4a 100644
--- a/src/kits/network/libnet/getnetnamadr.c
+++ b/src/kits/network/libnet/getnetnamadr.c
@@ -83,6 +83,8 @@
 #include <errno.h>
 #include <string.h>
 
+#undef h_errno
+	// was defined by netdb.h
 extern int h_errno;
 
 struct netent *_getnetbyaddr (in_addr_t net, int type);
diff --git a/src/kits/network/libnet/res_debug.c b/src/kits/network/libnet/res_debug.c
index 089bf90d2c..dc16b3b671 100644
--- a/src/kits/network/libnet/res_debug.c
+++ b/src/kits/network/libnet/res_debug.c
@@ -91,6 +91,9 @@
 #include <stdlib.h>
 #include <string.h>
 
+#undef h_errno
+	// was defined by netdb.h
+
 extern const char *_res_opcodes[];
 extern const char *_res_resultcodes[];
 
diff --git a/src/kits/network/libnet/res_mkquery.c b/src/kits/network/libnet/res_mkquery.c
index cc573842c7..eca7749a45 100644
--- a/src/kits/network/libnet/res_mkquery.c
+++ b/src/kits/network/libnet/res_mkquery.c
@@ -64,6 +64,9 @@
 #include <resolv.h>
 #include <string.h>
 
+#undef h_errno
+	// was defined by netdb.h
+
 /*
  * Form all types of queries.
  * Returns the size of the result or -1.
diff --git a/src/kits/network/libnet/res_query.c b/src/kits/network/libnet/res_query.c
index 3b45b8e02d..b6db3acfa4 100644
--- a/src/kits/network/libnet/res_query.c
+++ b/src/kits/network/libnet/res_query.c
@@ -75,7 +75,9 @@
 #endif
 
 const char *hostalias (const char *);
-int h_errno;
+#undef h_errno
+	// was defined by netdb.h
+int h_errno = 0;
 extern int res_opt (int, u_char *, int, int);
 
 /*