diff --git a/src/os_unix.c b/src/os_unix.c
index a5f033d..5e11eea 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -1471,6 +1471,9 @@
 {
     /* This function should not return, it causes exit().  Longjump instead. */
     LONGJMP(lc_jump_env, 1);
+#  ifdef VMS
+    return 0;  /* avoid the compiler complains about missing return value */
+#  endif
 }
 # endif
 
@@ -1490,6 +1493,9 @@
 
     /* This function should not return, it causes exit().  Longjump instead. */
     LONGJMP(x_jump_env, 1);
+# ifdef VMS
+    return 0;  /* avoid the compiler complains about missing return value */
+# endif
 }
 #endif