diff --git a/headers/posix/signal.h b/headers/posix/signal.h
index c8aec22f9d..97703c8976 100644
--- a/headers/posix/signal.h
+++ b/headers/posix/signal.h
@@ -174,8 +174,6 @@ int		sighold(int signo);
 int		sigrelse(int signo);
 int		sigpause(int signo);
 
-const char *strsignal(int sig);
-
 void	set_signal_stack(void *ptr, size_t size);
 int		sigaltstack(const stack_t *ss, stack_t *oss);
 
diff --git a/headers/posix/stdio.h b/headers/posix/stdio.h
index cfdf670953..ca3b95199b 100644
--- a/headers/posix/stdio.h
+++ b/headers/posix/stdio.h
@@ -135,8 +135,6 @@ extern int		fgetc(FILE *stream);
 extern char		*gets(char *buffer);
 extern char		*fgets(char *string, int stringLength, FILE *stream);
 
-extern char		*fgetln(FILE *stream, size_t *);
-
 /* formatted I/O */
 extern int		printf(char const *format, ...) __PRINTFLIKE(1,2);
 extern int		fprintf(FILE *stream, char const *format, ...) __PRINTFLIKE(2,3);
diff --git a/headers/posix/stdlib.h b/headers/posix/stdlib.h
index 20715bd7a9..0544c8af2e 100644
--- a/headers/posix/stdlib.h
+++ b/headers/posix/stdlib.h
@@ -60,7 +60,6 @@ extern void		exit(int);
 /* misc functions */
 extern char		*realpath(const char *path, char *resolved);
 
-extern int		daemon(int nochdir, int noclose);
 extern int		system(const char *command);
 
 extern char		*mktemp(char *name);
diff --git a/headers/posix/unistd.h b/headers/posix/unistd.h
index ad47b68fd7..778a109f6f 100644
--- a/headers/posix/unistd.h
+++ b/headers/posix/unistd.h
@@ -190,7 +190,6 @@ extern unsigned	int	alarm(unsigned int seconds);
 extern useconds_t	ualarm(useconds_t microSeconds, useconds_t interval);
 extern unsigned int	sleep(unsigned int seconds);
 extern int			usleep(unsigned int microSeconds);
-extern clock_t		clock(void);
 extern int 			pause(void);
 
 /* process */
@@ -206,7 +205,7 @@ extern pid_t	setpgrp(void);
 
 extern int		chroot(const char *path);
 
-/* access permissions */				
+/* access permissions */
 extern gid_t	getegid(void);
 extern uid_t	geteuid(void);
 extern gid_t	getgid(void);
@@ -247,9 +246,6 @@ extern void 	swab(const void *src, void *dest, ssize_t nbytes);
 extern char *optarg;
 extern int optind, opterr, optopt;
 
-/* ToDo: should be moved to stdlib.h */
-extern char **environ;
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/add-ons/tracker/zipomatic/ZipperThread.h b/src/add-ons/tracker/zipomatic/ZipperThread.h
index 6871dd6640..c0f099b084 100644
--- a/src/add-ons/tracker/zipomatic/ZipperThread.h
+++ b/src/add-ons/tracker/zipomatic/ZipperThread.h
@@ -10,6 +10,7 @@
 
 
 #include <stdio.h>
+#include <stdlib.h>
 
 #include <Message.h>
 #include <Messenger.h>
@@ -41,7 +42,7 @@ protected:
 private:
 			void			_MakeShellSafe(BString* string);
 
-			thread_id		_PipeCommand(int argc, const char** argv, 
+			thread_id		_PipeCommand(int argc, const char** argv,
 								int& in, int& out, int& err,
 								const char** envp = (const char**)environ);