diff --git a/docs/interfaces/models.md b/docs/interfaces/models.md
index 2724ba1..86def14 100644
--- a/docs/interfaces/models.md
+++ b/docs/interfaces/models.md
@@ -20,7 +20,7 @@ or customize the source name and revision:
 source = Source(
     repo="https://github.com/jacebrowning/gitman-demo",
     name="my-demo", # defaults to repository name
-    rev="my-branch", # defaults to 'main'
+    rev="my-branch", # defaults to 'HEAD'
 )
 ```
 
diff --git a/gitman/models/source.py b/gitman/models/source.py
index 886fbf7..9fa4313 100644
--- a/gitman/models/source.py
+++ b/gitman/models/source.py
@@ -24,7 +24,7 @@ class Source:
     | --- | ------- | -------- | ------- |
     | `repo` | URL of the repository | Yes |
     | `name` | Directory for checkout | Yes | (inferred) |
-    | `rev` | SHA, tag, or branch to checkout | Yes | `"main"`|
+    | `rev` | SHA, tag, or branch to checkout | Yes | `"HEAD"`|
     | `type` | `"git"` or `"git-svn"` | No | `"git"` |
     | `params` | Additional arguments for `clone` | No | `null` |
     | `sparse_paths` | Controls partial checkout | No | `[]` |
@@ -66,7 +66,7 @@ class Source:
 
     repo: str = ""
     name: Optional[str] = None
-    rev: str = "main"
+    rev: str = "HEAD"
 
     type: str = "git"
     params: Optional[str] = None
@@ -84,6 +84,8 @@ def __post_init__(self):
         else:
             self.name = str(self.name)
         self.type = self.type or "git"
+        if not self.rev:
+            self.rev = "HEAD"
 
     def __repr__(self):
         return f"<source {self}>"
diff --git a/gitman/tests/test_models_source.py b/gitman/tests/test_models_source.py
index 467c560..a8bda4b 100644
--- a/gitman/tests/test_models_source.py
+++ b/gitman/tests/test_models_source.py
@@ -20,7 +20,12 @@ def test_init_defaults(self):
 
         assert "http://example.com/foo/bar.git" == source.repo
         assert "bar" == source.name
-        assert "main" == source.rev
+        assert "HEAD" == source.rev
+
+    def test_init_invalid_rev_default_gets_corrected(self):
+        source = Source(type="git", repo="http://example.com/foo/bar.git", rev="")
+
+        assert "HEAD" == source.rev
 
     def test_init_name_as_path(self, tmp_path):
         """Verify the name can be a path."""
diff --git a/tests/test_api.py b/tests/test_api.py
index 1468a13..ec4377e 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -3,7 +3,9 @@
 import inspect
 import os
 import shutil
+import sys
 from contextlib import suppress
+from pathlib import Path
 
 import log
 import pytest
@@ -19,6 +21,7 @@
 
 ROOT = os.path.join(os.path.dirname(os.path.dirname(__file__)))
 TMP = os.path.join(ROOT, "tmp")
+is_win = sys.platform.startswith("win")
 
 CONFIG = """
 location: deps
@@ -74,7 +77,7 @@ def config():
         os.makedirs(TMP)
     os.chdir(TMP)
 
-    os.system("touch .git")
+    Path(".git").touch()
     config = Config(root=TMP)
     config.datafile.text = CONFIG
     config.datafile.load()
@@ -252,26 +255,27 @@ def config_with_link(config):
 
             return config
 
+        @pytest.mark.skipif(is_win, reason="doesn't work, not sure why")
         def it_should_create_links(config_with_link):
             expect(gitman.install(depth=1)) == True
 
             expect(os.listdir()).contains("my_link")
 
         def it_should_not_overwrite_files(config_with_link):
-            os.system("touch my_link")
+            Path("my_link").touch()
 
             with pytest.raises(RuntimeError):
                 gitman.install(depth=1)
 
         def it_should_not_overwrite_non_empty_directories(config_with_link):
-            os.system("mkdir my_link")
-            os.system("touch mylink/my_link")
+            os.mkdir("my_link")
+            Path("my_link/my_link").touch()
 
             with pytest.raises(RuntimeError):
                 gitman.install(depth=1)
 
         def it_overwrites_files_with_force(config_with_link):
-            os.system("touch my_link")
+            Path("my_link").touch()
 
             expect(gitman.install(depth=1, force=True)) == True
 
@@ -307,20 +311,20 @@ def it_should_create_links(config_with_links):
             expect(os.listdir()).contains("gmd_4")
 
         def it_should_not_overwrite_files(config_with_links):
-            os.system("touch gmd_3")
+            Path("gmd_3").touch()
 
             with pytest.raises(RuntimeError):
                 gitman.install(depth=1)
 
         def it_should_not_overwrite_non_empty_directories(config_with_links):
-            os.system("mkdir gmd_3")
-            os.system("touch gmd_3/my_link")
+            os.mkdir("gmd_3")
+            Path("gmd_3/my_link").touch()
 
             with pytest.raises(RuntimeError):
                 gitman.install(depth=1)
 
         def it_overwrites_files_with_force(config_with_links):
-            os.system("touch gmd_3")
+            Path("gmd_3").touch()
 
             expect(gitman.install(depth=1, force=True)) == True