diff --git a/support/appveyor-build.py b/support/appveyor-build.py
index 8a4ecaf0..17a24408 100755
--- a/support/appveyor-build.py
+++ b/support/appveyor-build.py
@@ -12,7 +12,7 @@ if build == 'mingw':
   build_command = ['mingw32-make', '-j4']
   test_command = ['mingw32-make', 'test']
   # Remove the path to Git bin directory from $PATH because it breaks MinGW config.
-  path = os.environ['PATH'].replace(r'C:\Program Files (x86)\Git\bin', '')
+  os.environ['PATH'] = os.environ['PATH'].replace(r'C:\Program Files (x86)\Git\bin', '')
 else:
   build_command = ['msbuild', '/m:4', '/p:Config=' + config, 'FORMAT.sln']
   test_command = ['msbuild', 'RUN_TESTS.vcxproj']