diff --git a/test/find_parent_dir.tcl b/test/find_parent_dir.tcl
deleted file mode 100644
index fe775507..00000000
--- a/test/find_parent_dir.tcl
+++ /dev/null
@@ -1,34 +0,0 @@
-#! /bin/sh
-# The next line is executed by /bin/sh, but not Tcl \
-exec tclsh $0 ${1+"$@"}
-
-# OpenSTA, Static Timing Analyzer
-# Copyright (c) 2019, Parallax Software, Inc.
-# 
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-# 
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-# 
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-proc find_parent_dir { dir } {
-  if { $dir == "." } {
-    return ".."
-  } else {
-    set path [file split $dir]
-    set path_len [llength $path]
-    if { $path_len == 1 } {
-      return "."
-    } else {
-      set path_len2 [expr $path_len - 2]
-      return [eval file join [lrange $path 0 $path_len2]]
-    }
-  }
-}
diff --git a/test/regression b/test/regression
index 577b7af9..f82c0fe7 100755
--- a/test/regression
+++ b/test/regression
@@ -23,7 +23,6 @@ exec tclsh $0 ${1+"$@"}
 
 # Directory containing tests.
 set test_dir [file dirname [file normalize [info script]]]
-source [file join $test_dir find_parent_dir.tcl]
 source [file join $test_dir regression_vars.tcl]
 source [file join $test_dir regression.tcl]
 
diff --git a/test/regression_vars.tcl b/test/regression_vars.tcl
index c3484c63..47e2ddd1 100644
--- a/test/regression_vars.tcl
+++ b/test/regression_vars.tcl
@@ -22,7 +22,7 @@ if { [regexp "CYGWIN" [exec uname -a]] } {
 } else {
   set app "sta"
 }
-set sta_dir [find_parent_dir $test_dir]
+set sta_dir [file dirname $test_dir]
 set app_path [file join $sta_dir "app" $app]
 # Application options.
 set app_options "-no_init -no_splash -exit"
diff --git a/test/save_ok b/test/save_ok
index d1277d3b..9fe6bc43 100755
--- a/test/save_ok
+++ b/test/save_ok
@@ -20,8 +20,6 @@ exec tclsh $0 ${1+"$@"}
 
 # Directory containing tests.
 set test_dir [file dirname [info script]]
-source [file join $test_dir find_parent_dir.tcl]
-set sta_dir [find_parent_dir $test_dir]
 source [file join $test_dir regression_vars.tcl]
 source [file join $test_dir regression.tcl]