diff --git a/fmusim-gui/build/build_cvode.py b/fmusim-gui/build/build_cvode.py
index 1f5a87d7..4b635019 100644
--- a/fmusim-gui/build/build_cvode.py
+++ b/fmusim-gui/build/build_cvode.py
@@ -28,12 +28,12 @@
     '-D', f'BUILD_TESTING=OFF',
     '-D', f'EXAMPLES_INSTALL=OFF',
     '-D', f'CMAKE_INSTALL_PREFIX={ install_prefix }',
-    root / 'cvode-6.4.1']
+    str(root / 'cvode-6.4.1')]
 )
 
 check_call([
     'cmake',
-    '--build', build_dir,
+    '--build', str(build_dir),
     '--config', 'Release',
     '--target', 'install'
 ])
diff --git a/fmusim-gui/build/build_libxml2.py b/fmusim-gui/build/build_libxml2.py
index cdd58195..10e147fa 100644
--- a/fmusim-gui/build/build_libxml2.py
+++ b/fmusim-gui/build/build_libxml2.py
@@ -31,12 +31,12 @@
     '-D', 'LIBXML2_WITH_PYTHON=OFF',
     '-D', 'LIBXML2_WITH_ZLIB=OFF',
     '-D', 'LIBXML2_WITH_TESTS=OFF',
-    root / 'libxml2-2.11.5']
+    str(root / 'libxml2-2.11.5')]
 )
 
 check_call([
     'cmake',
-    '--build', build_dir,
+    '--build', str(build_dir),
     '--config', 'Release',
     '--target', 'install'
 ])
diff --git a/fmusim-gui/build/build_zlib.py b/fmusim-gui/build/build_zlib.py
index ad375ad0..57673512 100644
--- a/fmusim-gui/build/build_zlib.py
+++ b/fmusim-gui/build/build_zlib.py
@@ -26,12 +26,12 @@
     cmake_args +
     ['-B', build_dir,
     '-D', f'CMAKE_INSTALL_PREFIX={ install_prefix }',
-    root / 'zlib-1.3']
+    str(root / 'zlib-1.3')]
 )
 
 check_call([
     'cmake',
-    '--build', build_dir,
+    '--build', str(build_dir),
     '--config', 'Release',
     '--target', 'install'
 ])