diff -ru make-4.1/main.c make-4.1-modified/main.c
--- make-4.1/main.c	2014-10-05 09:24:51.000000000 -0700
+++ make-4.1-modified/main.c	2016-05-10 15:35:50.701482697 -0700
@@ -1401,13 +1401,18 @@
 #ifdef HAVE_ISATTY
     if (isatty (fileno (stdout)))
       if (! lookup_variable (STRING_SIZE_TUPLE ("MAKE_TERMOUT")))
-        define_variable_cname ("MAKE_TERMOUT", TTYNAME (fileno (stdout)),
-                               o_default, 0)->export = v_export;
-
+      {
+          const char *tty = TTYNAME (fileno (stdout));
+          define_variable_cname ("MAKE_TERMOUT", tty ? tty : DEFAULT_TTYNAME,
+                                 o_default, 0)->export = v_export;
+      }
     if (isatty (fileno (stderr)))
       if (! lookup_variable (STRING_SIZE_TUPLE ("MAKE_TERMERR")))
-        define_variable_cname ("MAKE_TERMERR", TTYNAME (fileno (stderr)),
-                               o_default, 0)->export = v_export;
+      {
+          const char *tty = TTYNAME (fileno (stderr));
+          define_variable_cname ("MAKE_TERMERR", tty ? tty : DEFAULT_TTYNAME,
+                                 o_default, 0)->export = v_export;
+      }
 #endif
 
   /* Reset in case the switches changed our minds.  */
diff -ru make-4.1/makeint.h make-4.1-modified/makeint.h
--- make-4.1/makeint.h	2014-10-05 09:24:51.000000000 -0700
+++ make-4.1-modified/makeint.h	2016-05-10 15:37:24.421751458 -0700
@@ -424,10 +424,11 @@
 /* The number of bytes needed to represent the largest integer as a string.  */
 #define INTSTR_LENGTH         CSTRLEN ("18446744073709551616")
 
+#define DEFAULT_TTYNAME "true"
 #ifdef HAVE_TTYNAME
 # define TTYNAME(_f) ttyname (_f)
 #else
-# define TTYNAME(_f) "true"
+# define TTYNAME(_f) DEFAULT_TTYNAME
 #endif