diff --git a/Modules/CheckForPthreads.c b/Modules/CheckForPthreads.c
index 0f57245a7..2f0c203b5 100644
--- a/Modules/CheckForPthreads.c
+++ b/Modules/CheckForPthreads.c
@@ -5,8 +5,13 @@
 void* runner(void*);
 
 int res = 0;
-int main()
-{
+#ifdef __CLASSIC_C__
+int main(){
+  int ac;
+  char*av[];
+#else
+int main(int ac, char*av[]){
+#endif
   pthread_t tid[2];
   pthread_create(&tid[0], 0, runner, (void*)1);
   pthread_create(&tid[1], 0, runner, (void*)2);
@@ -14,7 +19,7 @@ int main()
   usleep(1); // for strange behavior on single-processor sun
   pthread_join(tid[0], 0);
   pthread_join(tid[1], 0);
-  
+  if(ac > 1000){return *av[0];}
   return res;
 }
 
diff --git a/Modules/CheckFunctionExists.c b/Modules/CheckFunctionExists.c
index e064c092e..607b3e8c6 100644
--- a/Modules/CheckFunctionExists.c
+++ b/Modules/CheckFunctionExists.c
@@ -1,16 +1,19 @@
 #ifdef CHECK_FUNCTION_EXISTS
 
 char CHECK_FUNCTION_EXISTS();
-
-int main(int ac, char*av[])
-{
-  int ret = 0;
+#ifdef __CLASSIC_C__
+int main(){
+  int ac;
+  char*av[];
+#else
+int main(int ac, char*av[]){
+#endif
   CHECK_FUNCTION_EXISTS();
-  if(ac > 100)
+  if(ac > 1000)
     {
-    ret = *av[0];
+    return *av[0];
     }
-  return ret;
+  return 0;
 }
 
 #else  /* CHECK_FUNCTION_EXISTS */
diff --git a/Modules/CheckTypeSize.c b/Modules/CheckTypeSize.c
index 43de43981..f8142892b 100644
--- a/Modules/CheckTypeSize.c
+++ b/Modules/CheckTypeSize.c
@@ -8,8 +8,14 @@
 #  include <stdint.h>
 #endif /* HAVE_STDINT_H */
 
-int main()
-{
+#ifdef __CLASSIC_C__
+int main(){
+  int ac;
+  char*av[];
+#else
+int main(int ac, char*av[]){
+#endif
+  if(ac > 1000){return *av[0];}
   return sizeof(CHECK_TYPE_SIZE_TYPE);
 }
 
diff --git a/Modules/CheckVariableExists.c b/Modules/CheckVariableExists.c
index e4d1e8dd7..419c1b02e 100644
--- a/Modules/CheckVariableExists.c
+++ b/Modules/CheckVariableExists.c
@@ -2,10 +2,16 @@
 
 extern int CHECK_VARIABLE_EXISTS;
 
-int main()
-{
+#ifdef __CLASSIC_C__
+int main(){
+  int ac;
+  char*av[];
+#else
+int main(int ac, char*av[]){
+#endif
   int* p;
   p = &CHECK_VARIABLE_EXISTS;
+  if(ac > 1000){return *av[0];}
   return 0;
 }
 
diff --git a/Modules/TestBigEndian.c b/Modules/TestBigEndian.c
index 97647edd0..db08ceb39 100644
--- a/Modules/TestBigEndian.c
+++ b/Modules/TestBigEndian.c
@@ -1,5 +1,10 @@
-int main (int ac, char*av[]) {
-  int ret = 1;
+#ifdef __CLASSIC_C__
+int main(){
+  int ac;
+  char*av[];
+#else
+int main(int ac, char*av[]){
+#endif
   /* Are we little or big endian?  From Harbison&Steele.  */
   union
   {
@@ -7,9 +12,6 @@ int main (int ac, char*av[]) {
     char c[sizeof (long)];
   } u;
   u.l = 1;
-  if(ac > 100)
-    {
-    ret = *av[0];
-    }
-  return (u.c[sizeof (long) - 1] == 1)?ret:0;
+  if(ac > 1000){return *av[0];}
+  return (u.c[sizeof (long) - 1] == 1)?1:0;
 }