diff --git a/boot/boot.c b/boot/boot.c
index ac42670a6..2201e61bc 100644
--- a/boot/boot.c
+++ b/boot/boot.c
@@ -1962,7 +1962,7 @@ void boot(void)
 
 #if UNIX
 
-void main(int argc, char **argv)
+int main(int argc, char **argv)
 /* Do not load or start anything, just edit parameters. */
 {
 	int i;
@@ -2034,6 +2034,7 @@ void main(int argc, char **argv)
 		monitor();
 	}
 	exit(0);
+	return 0;
 }
 
 reset() { }
diff --git a/boot/bootimage.c b/boot/bootimage.c
index 3638199b1..f2274176d 100644
--- a/boot/bootimage.c
+++ b/boot/bootimage.c
@@ -534,7 +534,7 @@ void exec_image(char *image)
 		/* Save a copy of the header for the kernel, with a_syms
 		 * misused as the address where the process is loaded at.
 		 */
-		DEBUGEXTRA(("raw_copy(0x%x, 0x%lx, 0x%x)... ", 
+		DEBUGEXTRA(("raw_copy(0x%lx, 0x%lx, 0x%x)... ", 
 			aout + i * A_MINHDR, mon2abs(&hdr.process), A_MINHDR));
 		hdr.process.a_syms= addr;
 		raw_copy(aout + i * A_MINHDR, mon2abs(&hdr.process), A_MINHDR);
@@ -653,7 +653,7 @@ void exec_image(char *image)
 	}
 
 	if (verboseboot < VERBOSEBOOT_BASIC)
-		printf("(%dk)\n", totalmem/1024);
+		printf("(%luk)\n", totalmem/1024);
 
 	if ((n_procs= i) == 0) {
 		printf("There are no programs in %s\n", image);
@@ -842,7 +842,7 @@ void bootminix(void)
 		printf("Not enough memory to load %s\n", image);
 		break;
 	case EIO:
-		printf("Unsuspected EOF on %s\n", image);
+		printf("Unexpected EOF on %s\n", image);
 	case 0:
 		/* No error or error already reported. */;
 	}
diff --git a/drivers/printer/printer.c b/drivers/printer/printer.c
index 905406ac0..7d02e0ec9 100644
--- a/drivers/printer/printer.c
+++ b/drivers/printer/printer.c
@@ -124,7 +124,7 @@ PUBLIC int is_status_msg_expected = FALSE;
 /*===========================================================================*
  *				printer_task				     *
  *===========================================================================*/
-PUBLIC void main(void)
+PUBLIC int main(int argc, char *argv[])
 {
 /* Main routine of the printer task. */
   message pr_mess;		/* buffer for all incoming messages */
diff --git a/drivers/sb16/dsp/sb16_dsp.c b/drivers/sb16/dsp/sb16_dsp.c
index 052c28bba..dbc98c163 100644
--- a/drivers/sb16/dsp/sb16_dsp.c
+++ b/drivers/sb16/dsp/sb16_dsp.c
@@ -28,7 +28,6 @@
 #include "sb16.h"
 
 
-_PROTOTYPE(void main, (void));
 FORWARD _PROTOTYPE( int dsp_open, (void) );
 FORWARD _PROTOTYPE( int dsp_close, (void) );
 FORWARD _PROTOTYPE( int dsp_ioctl, (const message *m_ptr) );
@@ -88,7 +87,7 @@ PUBLIC int is_status_msg_expected = FALSE;
 /*===========================================================================*
  *				main
  *===========================================================================*/
-PUBLIC void main() 
+PUBLIC int main(int argc, char *argv[]) 
 {	
 	int r;
 	endpoint_t caller;
diff --git a/drivers/sb16/mixer/sb16_mixer.c b/drivers/sb16/mixer/sb16_mixer.c
index d12024cff..c721a4c38 100644
--- a/drivers/sb16/mixer/sb16_mixer.c
+++ b/drivers/sb16/mixer/sb16_mixer.c
@@ -24,7 +24,6 @@
 #include "sb16.h"
 
 
-_PROTOTYPE(void main, (void));
 FORWARD _PROTOTYPE( int mixer_init, (void)); 
 FORWARD _PROTOTYPE( int mixer_open, (const message *m_ptr));
 FORWARD _PROTOTYPE( int mixer_close, (const message *m_ptr));
@@ -47,7 +46,8 @@ FORWARD _PROTOTYPE( int sef_cb_init_fresh, (int type, sef_init_info_t *info) );
 /*===========================================================================*
  *				main
  *===========================================================================*/
-PUBLIC void main() {
+PUBLIC int main(int argc, char *argv[])
+{
 	message mess;
 	int ipc_status;
 	int err, caller, proc_nr;
diff --git a/kernel/main.c b/kernel/main.c
index a5801bda3..ab7f4ed04 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -26,7 +26,7 @@ FORWARD _PROTOTYPE( void announce, (void));
 /*===========================================================================*
  *				main                                         *
  *===========================================================================*/
-PUBLIC void main(void)
+PUBLIC int main(int argc, char *argv[])
 {
 /* Start the ball rolling. */
   struct boot_image *ip;	/* boot image pointer */
@@ -260,6 +260,7 @@ PUBLIC void main(void)
 
   switch_to_user();
   NOT_REACHABLE;
+  return 1;
 }
 
 /*===========================================================================*
diff --git a/test/select/speed.c b/test/select/speed.c
index 889d3a4c8..46956b181 100644
--- a/test/select/speed.c
+++ b/test/select/speed.c
@@ -24,7 +24,8 @@
 
 #define NUMBER 12
 
-void main(void) {
+int main(int argc, char *argv[])
+{
 	char *udp_device;
 	int fd[NUMBER];
 	fd_set fds_write;
@@ -56,4 +57,5 @@ void main(void) {
 	for (i = 0; i < NUMBER; i++) {
 		close(fd[i]);
 	}
+	return 0;
 }
diff --git a/test/select/test02.c b/test/select/test02.c
index 93a2b2364..338565734 100644
--- a/test/select/test02.c
+++ b/test/select/test02.c
@@ -29,7 +29,8 @@ void dump_fdset(fd_set *set) {
 	printf("\n");
 }
 
-void main(void) {
+int main(int argc, char *argv[])
+{
 	int fd1, fd2, fd3, fd4, fd5, fd6;	/* file descriptors of files */
 	fd_set fds_read, fds_write;
 	int retval;
@@ -109,4 +110,5 @@ void main(void) {
 	unlink("dummy4.txt");
 	unlink("dummy5.txt");
 	unlink("dummy6.txt");
+	return 0;
 }
diff --git a/test/select/test03.c b/test/select/test03.c
index fcbb96556..14e2eba8d 100644
--- a/test/select/test03.c
+++ b/test/select/test03.c
@@ -1,5 +1,5 @@
 /*
- * Test name: test02.c
+ * Test name: test03.c
  *
  * Objetive: The purpose of this test is to make sure that select works
  * when working with files.
@@ -28,7 +28,8 @@ void dump_fdset(fd_set *set) {
 	printf("\n");
 }
 
-void main(void) {
+int main(int argc, char *argv[])
+{
 	int fd1, fd2, fd3, fd4, fd5, fd6;	/* file descriptors of files */
 	fd_set fds_read, fds_write;		/* bit maps */
 	struct timeval timeout;			/* timeout */
@@ -132,4 +133,5 @@ void main(void) {
 	unlink("dummy4.txt");
 	unlink("dummy5.txt");
 	unlink("dummy6.txt");
+	return 0;
 }
diff --git a/test/select/test10.c b/test/select/test10.c
index 3f44d829c..6f68c8490 100644
--- a/test/select/test10.c
+++ b/test/select/test10.c
@@ -22,7 +22,8 @@
 #include <limits.h>
 #include <string.h>
 
-void main(void) {
+int main(int argc, char *argv[])
+{
 	fd_set fds_read, fds_write;
 	int retval;
 	char data[1024];
@@ -66,4 +67,5 @@ void main(void) {
 		}
 		printf("Data: %s\n", data);
 	}
+	return 1;
 }
diff --git a/test/select/test11.c b/test/select/test11.c
index 5126f60cd..99c8381b8 100644
--- a/test/select/test11.c
+++ b/test/select/test11.c
@@ -137,7 +137,8 @@ void do_parent(int data_pipe[])
 	exit(0);
 }
 
-void main(void) {
+int main(int argc, char *argv[])
+{
 	int pipes[2];
 	int retval;
 	int pid;	
@@ -159,4 +160,5 @@ void main(void) {
 		do_child(pipes);
 	else
 		do_parent(pipes);
+	return 0;
 }
diff --git a/test/test17.c b/test/test17.c
index df0afd915..8eb011882 100644
--- a/test/test17.c
+++ b/test/test17.c
@@ -750,13 +750,12 @@ char *string;
 
 void nlcr()
 {
-  printf("\n");
+  fputs("\n",stdout);
 }
 
-void str(s)
-char *s;
+void str(char *s)
 {
-  printf(s);
+  fputs(s,stdout);
 }
 
 /*****************************************************************************
diff --git a/test/test18.c b/test/test18.c
index 17fbf4aa0..e59e51dc4 100644
--- a/test/test18.c
+++ b/test/test18.c
@@ -999,13 +999,12 @@ char *string;
 
 void nlcr()
 {
-  printf("\n");
+  fputs("\n",stdout);
 }
 
-void str(s)
-char *s;
+void str(char *s)
 {
-  printf(s);
+  fputs(s,stdout);
 }
 
 /*****************************************************************************
diff --git a/test/test20.c b/test/test20.c
index 3fb628402..68b2aaf04 100644
--- a/test/test20.c
+++ b/test/test20.c
@@ -35,7 +35,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test20a, (void));
 _PROTOTYPE(void test20b, (void));
 _PROTOTYPE(void test20c, (void));
@@ -47,9 +46,7 @@ _PROTOTYPE(void quit, (void));
 
 char executable[1024];
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
diff --git a/test/test22.c b/test/test22.c
index 1c5d00a68..20249ac2b 100644
--- a/test/test22.c
+++ b/test/test22.c
@@ -19,16 +19,13 @@
 int errct = 0;			/* Total error counter. */
 int subtest = 1;
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test22a, (void));
 _PROTOTYPE(int mode, (char *filename));
 _PROTOTYPE(int umode, (char *filename));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
diff --git a/test/test23.c b/test/test23.c
index 2a1dceeb6..05c5bfdb3 100644
--- a/test/test23.c
+++ b/test/test23.c
@@ -29,7 +29,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test23a, (void));
 _PROTOTYPE(void test23b, (void));
 _PROTOTYPE(void test23c, (void));
@@ -39,9 +38,7 @@ _PROTOTYPE(char *my_getcwd, (char *buf, int size));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -61,6 +58,7 @@ char *argv[];
   }
 
   quit();
+  return 1;
 }
 
 void test23a()
diff --git a/test/test24.c b/test/test24.c
index a821bf8b6..411b80990 100644
--- a/test/test24.c
+++ b/test/test24.c
@@ -13,7 +13,6 @@
 #include <time.h>
 #include <stdio.h>
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void chk_dir, (DIR * dirpntr));
 _PROTOTYPE(void test24a, (void));
 _PROTOTYPE(void test24b, (void));
@@ -39,9 +38,7 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
diff --git a/test/test25.c b/test/test25.c
index a05943030..2bd7c39c9 100644
--- a/test/test25.c
+++ b/test/test25.c
@@ -33,7 +33,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test25a, (void));
 _PROTOTYPE(void test25b, (void));
 _PROTOTYPE(void test25c, (void));
@@ -43,9 +42,7 @@ _PROTOTYPE(void makelongnames, (void));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   char buffer[PATH_MAX + 1];
   int i, m = 0xFFFF;
@@ -77,6 +74,7 @@ char *argv[];
 	if (m & 020) test25e();
   }
   quit();
+  return 1;
 }
 
 void test25a()
diff --git a/test/test26.c b/test/test26.c
index 729041732..998e9e9af 100644
--- a/test/test26.c
+++ b/test/test26.c
@@ -27,16 +27,13 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test26a, (void));
 _PROTOTYPE(void test26b, (void));
 _PROTOTYPE(void test26c, (void));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
diff --git a/test/test27.c b/test/test27.c
index 491f6b7ff..a7659cc4e 100644
--- a/test/test27.c
+++ b/test/test27.c
@@ -27,7 +27,6 @@ char MaxPath[PATH_MAX];
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test27a, (void));
 _PROTOTYPE(void test27b, (void));
 _PROTOTYPE(void test27c, (void));
@@ -35,9 +34,7 @@ _PROTOTYPE(void makelongnames, (void));
 _PROTOTYPE(void e, (int __n));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
diff --git a/test/test28.c b/test/test28.c
index 223726c84..46b2ddecd 100644
--- a/test/test28.c
+++ b/test/test28.c
@@ -36,7 +36,6 @@ char MaxPath[PATH_MAX];
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test28a, (void));
 _PROTOTYPE(void test28c, (void));
 _PROTOTYPE(void test28b, (void));
@@ -44,9 +43,7 @@ _PROTOTYPE(void makelongnames, (void));
 _PROTOTYPE(void e, (int n));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -67,6 +64,7 @@ char *argv[];
 	if (m & 0004) test28c();
   }
   quit();
+  return 1;
 }
 
 void test28a()
diff --git a/test/test29.c b/test/test29.c
index 64da56056..5e209e1b7 100644
--- a/test/test29.c
+++ b/test/test29.c
@@ -42,16 +42,13 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test29a, (void));
 _PROTOTYPE(void test29b, (void));
 _PROTOTYPE(void test29c, (void));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
diff --git a/test/test30.c b/test/test30.c
index 879ce77ab..586197c8e 100644
--- a/test/test30.c
+++ b/test/test30.c
@@ -34,7 +34,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test30a, (void));
 _PROTOTYPE(void test30b, (void));
 _PROTOTYPE(void test30c, (void));
@@ -42,9 +41,7 @@ _PROTOTYPE(void makelongnames, (void));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -118,7 +115,7 @@ void test30a()
   if (st.st_gid != getegid()) e(10);
 #endif /* defined(NGROUPS_MAX) && NGROUPS_MAX == 0 */
   if (!S_ISREG(st.st_mode)) e(11);
-  if (st.st_mode & 0777 != 0644) e(12);
+  if ((st.st_mode & 0777) != 0644) e(12);
   if (st.st_nlink != 1) e(13);
   if (st.st_ctime != time1) e(14);	/* All time fields should be updated */
   if (st.st_atime != time1) e(15);
diff --git a/test/test31.c b/test/test31.c
index 3acf7275a..412bfe7ea 100644
--- a/test/test31.c
+++ b/test/test31.c
@@ -27,7 +27,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test31a, (void));
 _PROTOTYPE(void test31b, (void));
 _PROTOTYPE(void test31c, (void));
@@ -35,9 +34,7 @@ _PROTOTYPE(void makelongnames, (void));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -58,6 +55,7 @@ char *argv[];
 	if (m & 0004) test31c();
   }
   quit();
+  return 1;
 }
 
 void test31a()
@@ -96,7 +94,7 @@ void test31a()
   if (st.st_gid != getegid()) e(4);
 #endif /* defined(NGROUPS_MAX) && NGROUPS_MAX == 0 */
   if (!S_ISFIFO(st.st_mode)) e(5);
-  if (st.st_mode & 0777 != 0644) e(6);
+  if ((st.st_mode & 0777) != 0644) e(6);
   if (st.st_nlink != 1) e(7);
   if (st.st_ctime != time1) e(8);
   if (st.st_atime != time1) e(9);
diff --git a/test/test32.c b/test/test32.c
index 23bd89534..c04b0ca6a 100644
--- a/test/test32.c
+++ b/test/test32.c
@@ -28,7 +28,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test32a, (void));
 _PROTOTYPE(void test32b, (void));
 _PROTOTYPE(void test32c, (void));
@@ -36,9 +35,7 @@ _PROTOTYPE(void makelongnames, (void));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -57,6 +54,7 @@ char *argv[];
 	if (m & 0004) test32c();
   }
   quit();
+  return 1;
 }
 
 #define BUF_SIZE 1024
diff --git a/test/test33.c b/test/test33.c
index 841bed64f..3ed79bf60 100644
--- a/test/test33.c
+++ b/test/test33.c
@@ -29,7 +29,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test33a, (void));
 _PROTOTYPE(void test33b, (void));
 _PROTOTYPE(void test33c, (void));
@@ -39,9 +38,7 @@ _PROTOTYPE(void makelongnames, (void));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -72,6 +69,7 @@ char *argv[];
 	if (m & 0010) test33d();
   }
   quit();
+  return 1;
 }
 
 void test33a()
diff --git a/test/test34.c b/test/test34.c
index d1f7f386a..1948573e3 100644
--- a/test/test34.c
+++ b/test/test34.c
@@ -46,7 +46,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char NameTooLong[NAME_MAX + 2];	/* Name of maximum +1 length */
 char PathTooLong[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test34a, (void));
 _PROTOTYPE(void test34b, (void));
 _PROTOTYPE(void test34c, (void));
@@ -56,9 +55,7 @@ _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 _PROTOTYPE(void getids, (uid_t * uid, gid_t * gid));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
diff --git a/test/test35.c b/test/test35.c
index 94cd13ec1..5bb151ae0 100644
--- a/test/test35.c
+++ b/test/test35.c
@@ -39,7 +39,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char NameTooLong[NAME_MAX + 2];	/* Name of maximum +1 length */
 char PathTooLong[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test35a, (void));
 _PROTOTYPE(void test35b, (void));
 _PROTOTYPE(void test35c, (void));
@@ -48,9 +47,7 @@ _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 _PROTOTYPE(void getids, (uid_t * uid, gid_t * gid));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -79,6 +76,7 @@ char *argv[];
 	if (m & 0004) test35c();
   }
   quit();
+  return 1;
 }
 
 void test35a()
diff --git a/test/test36.c b/test/test36.c
index 1d820539c..40163c050 100644
--- a/test/test36.c
+++ b/test/test36.c
@@ -27,7 +27,6 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test36a, (void));
 _PROTOTYPE(void test36b, (void));
 _PROTOTYPE(void test36c, (void));
@@ -61,9 +60,7 @@ char *testfiles[] = {
 	     NULL
 };
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -83,6 +80,7 @@ char *argv[];
 	if (m & 0010) test36d();
   }
   quit();
+  return 1;
 }
 
 void test36a()
diff --git a/test/test38.c b/test/test38.c
index 66ddf79ea..d3eae8ec3 100644
--- a/test/test38.c
+++ b/test/test38.c
@@ -31,7 +31,6 @@ int subtest = 1;
 int superuser;
 int signumber = 0;
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test38a, (void));
 _PROTOTYPE(void test38b, (void));
 _PROTOTYPE(void test38c, (void));
@@ -39,9 +38,7 @@ _PROTOTYPE(void setsignumber, (int _signumber));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -60,6 +57,7 @@ char *argv[];
 	if (m & 0004) test38c();
   }
   quit();
+  return 1;
 }
 
 void test38a()
diff --git a/test/test53.c b/test/test53.c
index e2d57b5de..aea34051a 100644
--- a/test/test53.c
+++ b/test/test53.c
@@ -12,7 +12,7 @@
 #define TIMED 0
 
 static volatile int errct;
-static volatile expect_SIGFPE;
+static volatile int expect_SIGFPE;
 static u64_t i, j, k;
 static jmp_buf jmpbuf_SIGFPE, jmpbuf_main;
 
diff --git a/test/test8.c b/test/test8.c
index 9eb215f20..0ddd7295f 100644
--- a/test/test8.c
+++ b/test/test8.c
@@ -25,15 +25,12 @@ char MaxPath[PATH_MAX];		/* Same for path */
 char ToLongName[NAME_MAX + 2];	/* Name of maximum +1 length */
 char ToLongPath[PATH_MAX + 1];	/* Same for path, both too long */
 
-_PROTOTYPE(void main, (int argc, char *argv[]));
 _PROTOTYPE(void test8a, (void));
 _PROTOTYPE(void test8b, (void));
 _PROTOTYPE(void e, (int number));
 _PROTOTYPE(void quit, (void));
 
-void main(argc, argv)
-int argc;
-char *argv[];
+int main(int argc, char *argv[])
 {
   int i, m = 0xFFFF;
 
@@ -47,6 +44,7 @@ char *argv[];
 	if (m & 0002) test8b();
   }
   quit();
+  return 1;
 }
 
 void test8a()
diff --git a/test/test9.c b/test/test9.c
index 2e63c989e..932825590 100644
--- a/test/test9.c
+++ b/test/test9.c
@@ -64,7 +64,7 @@ to the value they had at the time of the Setjmp\n");
 
 void test9a()
 {
-  register p;
+  register int p;
 
   subtest = 1;
   p = 200;
@@ -74,7 +74,7 @@ void test9a()
 
 void test9b()
 {
-  register p, q;
+  register int p, q;
 
   subtest = 2;
   p = 200;
@@ -86,7 +86,7 @@ void test9b()
 
 void test9c()
 {
-  register p, q, r;
+  register int p, q, r;
 
   subtest = 3;
   p = 200;
@@ -151,7 +151,7 @@ char *
 
 void garbage()
 {
-  register i, j, k;
+  register int i, j, k;
   register char *p, *q, *r;
   char *a;
 
@@ -226,7 +226,7 @@ void garbage()
 void level1()
 {
   register char *p;
-  register i;
+  register int i;
 
   i = 1000;
   p = &buf[10];
@@ -238,7 +238,7 @@ void level1()
 void level2()
 {
   register char *p;
-  register i;
+  register int i;
 
   i = 0200;
   p = &buf[2];
@@ -249,7 +249,7 @@ void level2()
 void dolev()
 {
   register char *p;
-  register i;
+  register int i;
 
   i = 010;
   p = &buf[3];