diff --git a/.travis.yml b/.travis.yml
index 922bc57..fd4fde0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -26,7 +26,7 @@ install:
   # Install dependencies for tests.
   - pip install -r tests/requirements.txt | cat
 
-  - pip install git+http://github.com/pyinstaller/pyinstaller
+  - pip install git+http://github.com/pyinstaller/pyinstaller@5f91905
 
   # Install qt4 from third-party source
   # https://github.com/cartr/homebrew-qt4
diff --git a/appveyor.yml b/appveyor.yml
index 7bce28b..bde5bd6 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -42,7 +42,7 @@ install:
   - "SET PATH=%PYTHON%;%PYTHON%\\Scripts;%PATH%"
   - pip install https://github.com/mcedit/mcedit2-deps/raw/master/wheels/PySide-1.2.2-cp27-none-win%WHL_ARCH%.whl
   - pip install -r requirements.txt
-  - pip install git+http://github.com/pyinstaller/pyinstaller
+  - pip install git+http://github.com/pyinstaller/pyinstaller@5f91905
 
 build_script:
   - pyinstaller mcedit2.spec