diff -ur a/utils/m-tx/mtx-src/prepmx.c b/utils/m-tx/mtx-src/prepmx.c
--- a/utils/m-tx/mtx-src/prepmx.c	2018-04-28 17:56:18.000000000 -0600
+++ b/utils/m-tx/mtx-src/prepmx.c	2023-07-11 15:21:26.351024424 -0600
@@ -769,6 +769,7 @@
 }
 
 
+int
 main(int argc, Char *argv[])
 {  /* ---- Main program ------------------------ */
   PASCAL_MAIN(argc, argv);
diff -ur a/utils/pmx/pmx-src/libf2c/main.c b/utils/pmx/pmx-src/libf2c/main.c
--- a/utils/pmx/pmx-src/libf2c/main.c	2016-02-09 22:31:26.000000000 -0700
+++ b/utils/pmx/pmx-src/libf2c/main.c	2023-07-11 15:49:35.043438384 -0600
@@ -106,6 +106,7 @@
 #ifdef KR_headers
 main(argc, argv) int argc; char **argv;
 #else
+int
 main(int argc, char **argv)
 #endif
 {