diff --git a/tox.ini b/tox.ini
index c3a981f80..4786d0e8f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -56,7 +56,7 @@ deps =
     devdeps: matplotlib>=0.0.dev0
     devdeps: pyerfa>=0.0.dev0
     devdeps: astropy>=0.0.dev0
-    devdeps: git+https://github.com/WilliamJamieson/gwcs.git@ignore_warnings_from_existing_files#egg=gwcs
+    devdeps: git+https://github.com/WilliamJamieson/gwcs.git@bugfix/ignore_warnings_from_existing_files#egg=gwcs
     devdeps: git+https://github.com/asdf-format/asdf.git
     devdeps: git+https://github.com/astropy/asdf-astropy.git
     devdeps: git+https://github.com/spacetelescope/stdatamodels.git