--- include/system.h
+++ include/system.h
@@ -87,14 +87,18 @@
 #  endif
 # endif
 #else
+# ifndef __GLIBC__
 E long lrand48();
 E void srand48();
+# endif
 #endif /* BSD || ULTRIX || RANDOM */
 
 #if !defined(BSD) || defined(ultrix)
 			/* real BSD wants all these to return int */
 # ifndef MICRO
+#  ifndef __GLIBC__
 E void FDECL(exit, (int));
+#  endif
 # endif /* MICRO */
 /* compensate for some CSet/2 bogosities */
 # if defined(OS2_CSET2) && defined(OS2_CSET2_VER_2)
@@ -113,7 +117,9 @@
 # if defined(__STDC__) || !defined(FLEX_SCANNER)
 #  ifndef OS2_CSET2
 #   ifndef MONITOR_HEAP
+#    ifndef __GLIBC__
 E void FDECL(free, (genericptr_t));
+#    endif
 #   endif
 #  endif
 # endif
@@ -346,26 +352,34 @@
 E void sleep();
 #endif
 #if defined(ULTRIX) || defined(SYSV)
+# ifndef __GLIBC__
 E unsigned sleep();
+# endif
 #endif
 #if defined(HPUX)
 E unsigned int FDECL(sleep, (unsigned int));
 #endif
 #ifdef VMS
+# ifndef __GLIBC__
 E int FDECL(sleep, (unsigned));
+# endif
 #endif
 
+#ifndef __GLIBC__
 E char *FDECL(getenv, (const char *));
 E char *getlogin();
+#endif
 #if defined(HPUX) && !defined(_POSIX_SOURCE)
 E long NDECL(getuid);
 E long NDECL(getgid);
 E long NDECL(getpid);
 #else
 # ifdef POSIX_TYPES
+#  ifndef __GLIBC__
 E pid_t NDECL(getpid);
 E uid_t NDECL(getuid);
 E gid_t NDECL(getgid);
+#  endif
 #  ifdef VMS
 E pid_t NDECL(getppid);
 #  endif
@@ -476,9 +490,11 @@
 #  if !defined(SVR4) && !defined(apollo)
 #   if !(defined(ULTRIX_PROTO) && defined(__GNUC__))
 #    if !(defined(SUNOS4) && defined(__STDC__)) /* Solaris unbundled cc (acc) */
+/*
 E int FDECL(vsprintf, (char *, const char *, va_list));
 E int FDECL(vfprintf, (FILE *, const char *, va_list));
 E int FDECL(vprintf, (const char *, va_list));
+*/
 #    endif
 #   endif
 #  endif