--- a/lib/getline.h
+++ b/lib/getline.h
@@ -27,6 +27,7 @@
 #  endif
 # endif
 
+# if defined (__GLIBC__)
 # if __GLIBC__ < 2
 int
 getline PARAMS ((char **_lineptr, size_t *_n, FILE *_stream));
@@ -34,5 +35,6 @@
 int
 getdelim PARAMS ((char **_lineptr, size_t *_n, int _delimiter, FILE *_stream));
 # endif
+# endif
 
 #endif /* not GETLINE_H_ */
--- a/lib/realloc.c
+++ b/lib/realloc.c
@@ -20,21 +20,15 @@
 #if HAVE_CONFIG_H
 # include <config.h>
 #endif
-#undef realloc
 
-#include <sys/types.h>
-
-char *malloc ();
-char *realloc ();
+#include <stdlib.h>
 
 /* Change the size of an allocated block of memory P to N bytes,
    with error checking.  If N is zero, change it to 1.  If P is NULL,
    use malloc.  */
 
 char *
-rpl_realloc (p, n)
-     char *p;
-     size_t n;
+rpl_realloc (char *p, size_t n)
 {
   if (n == 0)
     n = 1;
--- a/lib/xmalloc.c
+++ b/lib/xmalloc.c
@@ -20,15 +20,7 @@
 #endif
 
 #include <sys/types.h>
-
-#if STDC_HEADERS
-# include <stdlib.h>
-#else
-void *calloc ();
-void *malloc ();
-void *realloc ();
-void free ();
-#endif
+#include <stdlib.h>
 
 #if ENABLE_NLS
 # include <libintl.h>