diff --git a/src/pymod/unit_tests/pymod_tests.cc b/src/pymod/unit_tests/pymod_tests.cc
index 88cc5d7f4..3a5887407 100644
--- a/src/pymod/unit_tests/pymod_tests.cc
+++ b/src/pymod/unit_tests/pymod_tests.cc
@@ -20,6 +20,11 @@
 
 */
 
+#include "tlUnitTest.h"
+#include "tlStream.h"
+#include "tlFileUtils.h"
+#include "tlEnv.h"
+
 //  Oh my god ... STRINGIFY(s) will get the argument with MACROS REPLACED.
 //  So if the PYTHONPATH is something like build.linux-released, the "linux" macro
 //  set to 1 will make this "build.1-release". So STRINGIFY isn't a real solution.
@@ -30,22 +35,11 @@
 #define STRINGIFY(s) _STRINGIFY(s)
 #define _STRINGIFY(s) #s
 
-#include "tlUnitTest.h"
-#include "tlStream.h"
-
 int run_pymodtest (tl::TestBase *_this, const std::string &fn)
 {
-  static std::string pypath;
-  if (pypath.empty ()) {
-    pypath = "PYTHONPATH=";
-    pypath += STRINGIFY (PYTHONPATH);
-  }
-#if defined(_WIN32)
-  _putenv (const_cast<char *> (pypath.c_str ()));
-#else
-  putenv (const_cast<char *> (pypath.c_str ()));
-#endif
-  tl::info << pypath;
+  static std::string pypath = tl::combine_path (tl::get_inst_path (), "pymod");
+  tl::info << "PYTHONPATH=" << pypath;
+  tl::set_env ("PYTHONPATH", pypath);
 
   std::string fp (tl::testdata ());
   fp += "/pymod/";
diff --git a/src/pymod/unit_tests/unit_tests.pro b/src/pymod/unit_tests/unit_tests.pro
index 63ff2f443..b01660775 100644
--- a/src/pymod/unit_tests/unit_tests.pro
+++ b/src/pymod/unit_tests/unit_tests.pro
@@ -14,20 +14,14 @@ msvc {
   # "\\\\" is actually *one* backslash for replacement string and *two* backslashes in the
   # substitution string in qmake ... so we replace \ by \\ here:
   PYTHON_ESCAPED = $$replace(PYTHON, "\\\\", "\\\\")
-  PYTHONPATH = $$shell_path($$DESTDIR_UT/pymod)
-  PYTHONPATH_ESCAPED = $$replace(PYTHONPATH, "\\\\", "\\\\")
 
   QMAKE_CXXFLAGS += \
-    "-DPYTHON=\"$$PYTHON_ESCAPED\"" \
-    "-DPYTHONPATH=\"$$PYTHONPATH_ESCAPED\""
+    "-DPYTHON=\"$$PYTHON_ESCAPED\""
 
 } else {
 
-  PYTHONPATH = $$DESTDIR_UT/pymod
-
   DEFINES += \
     PYTHON=$$PYTHON \
-    PYTHONPATH=$$PYTHONPATH
 
 }
 
diff --git a/src/tl/tl/tlFileUtils.cc b/src/tl/tl/tlFileUtils.cc
index 2541a63ea..74d0ba77d 100644
--- a/src/tl/tl/tlFileUtils.cc
+++ b/src/tl/tl/tlFileUtils.cc
@@ -908,11 +908,11 @@ get_inst_path ()
 std::string
 get_exe_file ()
 {
-  static std::string s_inst_path;
-  if (s_inst_path.empty ()) {
-    s_inst_path = tl::absolute_file_path (get_inst_path_internal ());
+  static std::string s_exe_file;
+  if (s_exe_file.empty ()) {
+    s_exe_file = tl::absolute_file_path (get_inst_path_internal ());
   }
-  return s_inst_path;
+  return s_exe_file;
 }
 
 std::string