diff --git a/src/alloc.c b/src/alloc.c
index c741aa4..5b21993 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -12,8 +12,7 @@ static aligned realspace[SPACE / ALIGNMENT];
 #define space ((char *) realspace)
 static unsigned int avail = SPACE; /* multiple of ALIGNMENT; 0<=avail<=SPACE */
 
-/*@null@*//*@out@*/char *alloc(n)
-unsigned int n;
+/*@null@*//*@out@*/char *alloc(unsigned int n)
 {
   char *x;
   n = ALIGNMENT + n - (n & (ALIGNMENT - 1)); /* XXX: could overflow */
@@ -23,8 +22,7 @@ unsigned int n;
   return x;
 }
 
-void alloc_free(x)
-char *x;
+void alloc_free(char *x)
 {
   if (x >= space)
     if (x < space + SPACE)
diff --git a/src/alloc.h b/src/alloc.h
index 21122fc..4e0a406 100644
--- a/src/alloc.h
+++ b/src/alloc.h
@@ -3,8 +3,8 @@
 #ifndef ALLOC_H
 #define ALLOC_H
 
-extern /*@null@*//*@out@*/char *alloc();
-extern void alloc_free();
-extern int alloc_re();
+extern /*@null@*//*@out@*/char *alloc(unsigned int n);
+extern void alloc_free(char *x);
+extern int alloc_re(char **x, unsigned int m, unsigned int n);
 
 #endif
diff --git a/src/alloc_re.c b/src/alloc_re.c
index 1074609..0128fcf 100644
--- a/src/alloc_re.c
+++ b/src/alloc_re.c
@@ -3,10 +3,7 @@
 #include "alloc.h"
 #include "byte.h"
 
-int alloc_re(x,m,n)
-char **x;
-unsigned int m;
-unsigned int n;
+int alloc_re(char **x, unsigned int m, unsigned int n)
 {
   char *y;
  
diff --git a/src/byte.h b/src/byte.h
index 09aab61..d64ce9c 100644
--- a/src/byte.h
+++ b/src/byte.h
@@ -3,12 +3,11 @@
 #ifndef BYTE_H
 #define BYTE_H
 
-extern unsigned int byte_chr();
-extern unsigned int byte_rchr();
-extern void byte_copy();
-extern void byte_copyr();
-extern int byte_diff();
-extern void byte_zero();
+extern unsigned int byte_chr(char *s, register unsigned int n, int c);
+extern unsigned int byte_rchr(char *s, register unsigned int n, int c);
+extern void byte_copy(register char *to, register unsigned int n, register char *from);
+extern void byte_copyr(register char *to, register unsigned int n, register char *from);
+extern int byte_diff(register char *s, register unsigned int n, register char *t);
 
 #define byte_equal(s,n,t) (!byte_diff((s),(n),(t)))
 
diff --git a/src/byte_chr.c b/src/byte_chr.c
index fd56056..073a4ea 100644
--- a/src/byte_chr.c
+++ b/src/byte_chr.c
@@ -2,10 +2,7 @@
 
 #include "byte.h"
 
-unsigned int byte_chr(s,n,c)
-char *s;
-register unsigned int n;
-int c;
+unsigned int byte_chr(char *s, register unsigned int n, int c)
 {
   register char ch;
   register char *t;
diff --git a/src/byte_copy.c b/src/byte_copy.c
index 74c9e4a..bb8e40c 100644
--- a/src/byte_copy.c
+++ b/src/byte_copy.c
@@ -2,10 +2,7 @@
 
 #include "byte.h"
 
-void byte_copy(to,n,from)
-register char *to;
-register unsigned int n;
-register char *from;
+void byte_copy(register char *to, register unsigned int n, register char *from)
 {
   for (;;) {
     if (!n) return; *to++ = *from++; --n;
diff --git a/src/byte_cr.c b/src/byte_cr.c
index 52dc251..f6787f0 100644
--- a/src/byte_cr.c
+++ b/src/byte_cr.c
@@ -2,10 +2,7 @@
 
 #include "byte.h"
 
-void byte_copyr(to,n,from)
-register char *to;
-register unsigned int n;
-register char *from;
+void byte_copyr(register char *to, register unsigned int n, register char *from)
 {
   to += n;
   from += n;
diff --git a/src/byte_diff.c b/src/byte_diff.c
index 0c4d17b..f6559fa 100644
--- a/src/byte_diff.c
+++ b/src/byte_diff.c
@@ -2,10 +2,7 @@
 
 #include "byte.h"
 
-int byte_diff(s,n,t)
-register char *s;
-register unsigned int n;
-register char *t;
+int byte_diff(register char *s, register unsigned int n, register char *t)
 {
   for (;;) {
     if (!n) return 0; if (*s != *t) break; ++s; ++t; --n;
diff --git a/src/byte_rchr.c b/src/byte_rchr.c
index 7ea9948..69cf310 100644
--- a/src/byte_rchr.c
+++ b/src/byte_rchr.c
@@ -2,10 +2,7 @@
 
 #include "byte.h"
 
-unsigned int byte_rchr(s,n,c)
-char *s;
-register unsigned int n;
-int c;
+unsigned int byte_rchr(char *s, register unsigned int n, int c)
 {
   register char ch;
   register char *t;
diff --git a/src/wait.h b/src/wait.h
index d294e9d..2fb886c 100644
--- a/src/wait.h
+++ b/src/wait.h
@@ -3,10 +3,8 @@
 #ifndef WAIT_H
 #define WAIT_H
 
-extern int wait_pid();
-extern int wait_nohang();
-extern int wait_stop();
-extern int wait_stopnohang();
+extern int wait_pid(int *wstat, int pid);
+extern int wait_nohang(int *wstat);
 
 #define wait_crashed(w) ((w) & 127)
 #define wait_exitcode(w) ((w) >> 8)
diff --git a/src/wait_nohang.c b/src/wait_nohang.c
index 5c9c53d..27d6e17 100644
--- a/src/wait_nohang.c
+++ b/src/wait_nohang.c
@@ -4,7 +4,7 @@
 #include <sys/wait.h>
 #include "haswaitp.h"
 
-int wait_nohang(wstat) int *wstat;
+int wait_nohang(int *wstat)
 {
 #ifdef HASWAITPID
   return waitpid(-1,wstat,WNOHANG);
diff --git a/src/wait_pid.c b/src/wait_pid.c
index c2869b8..fe0d9e1 100644
--- a/src/wait_pid.c
+++ b/src/wait_pid.c
@@ -7,7 +7,7 @@
 
 #ifdef HASWAITPID
 
-int wait_pid(wstat,pid) int *wstat; int pid;
+int wait_pid(int *wstat, int pid)
 {
   int r;
 
@@ -24,7 +24,7 @@ int wait_pid(wstat,pid) int *wstat; int pid;
 static int oldpid = 0;
 static int oldwstat; /* defined if(oldpid) */
 
-int wait_pid(wstat,pid) int *wstat; int pid;
+int wait_pid(int *wstat, int pid)
 {
   int r;