diff -uNr m4-1.4.18/lib/tempname.c m4-1.4.18.mod/lib/tempname.c
--- m4-1.4.18/lib/tempname.c	2016-12-31 15:54:42.000000000 +0200
+++ m4-1.4.18.mod/lib/tempname.c	2019-03-01 20:52:48.978132063 +0200
@@ -32,7 +32,7 @@
 
 #include <stdio.h>
 #ifndef P_tmpdir
-# define P_tmpdir "/tmp"
+# define P_tmpdir "@TERMUX_PREFIX@/tmp"
 #endif
 #ifndef TMP_MAX
 # define TMP_MAX 238328
@@ -148,8 +148,8 @@
     {
       if (direxists (P_tmpdir))
         dir = P_tmpdir;
-      else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
-        dir = "/tmp";
+      else if (strcmp (P_tmpdir, "@TERMUX_PREFIX@/tmp") != 0 && direxists ("@TERMUX_PREFIX@/tmp"))
+        dir = "@TERMUX_PREFIX@/tmp";
       else
         {
           __set_errno (ENOENT);
diff -uNr m4-1.4.18/lib/tmpdir.c m4-1.4.18.mod/lib/tmpdir.c
--- m4-1.4.18/lib/tmpdir.c	2016-12-31 15:54:42.000000000 +0200
+++ m4-1.4.18.mod/lib/tmpdir.c	2019-03-01 20:53:16.521626327 +0200
@@ -36,7 +36,7 @@
 # ifdef _P_tmpdir /* native Windows */
 #  define P_tmpdir _P_tmpdir
 # else
-#  define P_tmpdir "/tmp"
+#  define P_tmpdir "@TERMUX_PREFIX@/tmp"
 # endif
 #endif
 
@@ -130,8 +130,8 @@
 #endif
       if (direxists (P_tmpdir))
         dir = P_tmpdir;
-      else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
-        dir = "/tmp";
+      else if (strcmp (P_tmpdir, "@TERMUX_PREFIX@/tmp") != 0 && direxists ("@TERMUX_PREFIX@/tmp"))
+        dir = "@TERMUX_PREFIX@/tmp";
       else
         {
           __set_errno (ENOENT);