--- a/configure.ac
+++ b/configure.ac
@@ -33,7 +33,7 @@ int main (int argc, char **argv)
 {
 MPI_Init(&argc,&argv);
 MPI_Finalize();
-exit(0);
+return 0;
 }
 EOF
 
@@ -105,7 +105,7 @@ cat > conftest.c <<EOF
 int main (int argc, char **argv)
 {
 printf ("%s-%s", PACKAGE, VERSION);
-exit(0);
+return 0;
 }
 EOF