diff --git a/sem b/sem
index 873f294..4fa24cb 100644
--- a/src/sem
+++ b/src/sem
@@ -2392,10 +2392,10 @@
     ## Shell
     #
     if($opt::fast) {
-	$Global::shell = $ENV{'PARALLEL_SHELL'} || which("dash") || "/bin/sh";
+	$Global::shell = $ENV{'PARALLEL_SHELL'} || which("dash") || "@TERMUX_PREFIX@/bin/sh";
     } else {
 	$Global::shell = $ENV{'PARALLEL_SHELL'} || parent_shell($$)
-	    || $ENV{'SHELL'} || "/bin/sh";
+	    || $ENV{'SHELL'} || "@TERMUX_PREFIX@/bin/sh";
     }
     if(not -x $Global::shell and not which($Global::shell)) {
 	::error("Shell '$Global::shell' not found.");
@@ -3080,15 +3080,15 @@
     $Global::trim = 'n';
     $Global::max_jobs_running = 0;
     $Global::job_already_run = '';
-    $ENV{'TMPDIR'} ||= "/tmp";
-    $ENV{'PARALLEL_REMOTE_TMPDIR'} ||= "/tmp";
+    $ENV{'TMPDIR'} ||= "@TERMUX_PREFIX@/tmp";
+    $ENV{'PARALLEL_REMOTE_TMPDIR'} ||= "@TERMUX_PREFIX@/tmp";
     # bug #55398: set $OLDPWD when using --wd
     $ENV{'OLDPWD'} = $ENV{'PWD'};
     test_safe_env_vars();
     if(not $ENV{HOME}) {
 	# $ENV{HOME} is sometimes not set if called from PHP
-	::warning("\$HOME not set. Using /tmp.");
-	$ENV{HOME} = "/tmp";
+	::warning("\$HOME not set. Using @TERMUX_PREFIX@/tmp.");
+	$ENV{HOME} = "@TERMUX_PREFIX@/tmp";
     }
     # no warnings to allow for undefined $XDG_*
     no warnings 'uninitialized';
@@ -5224,7 +5224,7 @@
     unlink $stderrname;
 
     my $pid = ::open3($stdin_fh,$stdout_fh,$stderr_fh,
-		      $0,qw(--plain --shell /bin/sh --will-cite), @args);
+		      $0,qw(--plain --shell @TERMUX_PREFIX@/bin/sh --will-cite), @args);
     if(my $writerpid = fork()) {
 	close $stdin_fh;
 	@stdout = <$stdout_fh>;