Fixed to pass -Wundef
diff --git a/coreutils/md5sum.c b/coreutils/md5sum.c
index fad563f..a791a41 100644
--- a/coreutils/md5sum.c
+++ b/coreutils/md5sum.c
@@ -96,7 +96,7 @@
#include <stdio.h>
-#if defined HAVE_LIMITS_H || _LIBC
+#if defined HAVE_LIMITS_H || defined _LIBC
# include <limits.h>
#endif
diff --git a/md5sum.c b/md5sum.c
index fad563f..a791a41 100644
--- a/md5sum.c
+++ b/md5sum.c
@@ -96,7 +96,7 @@
#include <stdio.h>
-#if defined HAVE_LIMITS_H || _LIBC
+#if defined HAVE_LIMITS_H || defined _LIBC
# include <limits.h>
#endif
diff --git a/networking/telnet.c b/networking/telnet.c
index 3e43c4a..40cf7a1 100644
--- a/networking/telnet.c
+++ b/networking/telnet.c
@@ -49,7 +49,7 @@
#define DOTRACE 1
#endif
-#if DOTRACE
+#ifdef DOTRACE
#include <arpa/inet.h> /* for inet_ntoa()... */
#define TRACE(x, y) do { if (x) printf y; } while (0)
#else
diff --git a/telnet.c b/telnet.c
index 3e43c4a..40cf7a1 100644
--- a/telnet.c
+++ b/telnet.c
@@ -49,7 +49,7 @@
#define DOTRACE 1
#endif
-#if DOTRACE
+#ifdef DOTRACE
#include <arpa/inet.h> /* for inet_ntoa()... */
#define TRACE(x, y) do { if (x) printf y; } while (0)
#else