diff --git a/pre_commit/main.py b/pre_commit/main.py
index 28c4f7147..0994067d4 100644
--- a/pre_commit/main.py
+++ b/pre_commit/main.py
@@ -25,6 +25,9 @@
 # https://github.com/pre-commit/pre-commit/issues/300
 # In git 2.6.3 (maybe others), git exports this while running pre-commit hooks
 os.environ.pop('GIT_WORK_TREE', None)
+# Don't trigger msysgit's wacky shell interpolation
+# For instance on cmd_output('echo', 'hi{1}')
+os.environ['MSYS'] = 'noglob'
 
 
 def main(argv=None):
diff --git a/tests/repository_test.py b/tests/repository_test.py
index f26b62311..91e9ff3e6 100644
--- a/tests/repository_test.py
+++ b/tests/repository_test.py
@@ -187,11 +187,11 @@ def test_run_hook_with_curly_braced_arguments(tempdir_factory, store):
         tempdir_factory, store, 'arg_per_line_hooks_repo',
         'arg-per-line',
         [],
-        b"arg: hi {1}\narg: I'm {a} problem\n",
+        b"arg: hi{1}\narg: I'm {a} problem\n",
         config_kwargs={
             'hooks': [{
                 'id': 'arg-per-line',
-                'args': ['hi {1}', "I'm {a} problem"],
+                'args': ['hi{1}', "I'm {a} problem"],
             }]
         },
     )