diff --git a/README.md b/README.md
index 2d8d756..fe4ffb6 100644
--- a/README.md
+++ b/README.md
@@ -50,10 +50,10 @@ Unlike standard actions, this action just uses variables from the environment.
 | PULL_REQUEST_ASSIGNEES | A list (string with spaces) of users to assign | false | unset |
 | PULL_REQUEST_REVIEWERS | A list (string with spaces) of users to assign review | false | unset |
 | PULL_REQUEST_TEAM_REVIEWERS | A list (string with spaces) of teams to assign review | false | unset |
-| PASS_ON_ERROR | Instead of failing on an error response, pass | unset |
-| PASS_IF_EXISTS | Instead of failing if the pull request already exists, pass | unset |
-| PULL_REQUEST_UPDATE | If the pull request already exists, update it | unset |
-| PULL_REQUEST_STATE | If `PULL_REQUEST_UPDATE` is true, update to this state (open, closed) | open |
+| PASS_ON_ERROR | Instead of failing on an error response, pass | false | unset |
+| PASS_IF_EXISTS | Instead of failing if the pull request already exists, pass | false | unset |
+| PULL_REQUEST_UPDATE | If the pull request already exists, update it | false | unset |
+| PULL_REQUEST_STATE | If `PULL_REQUEST_UPDATE` is true, update to this state (open, closed) | false |open |
 
 For `PULL_REQUEST_DRAFT`, `PASS_ON_ERROR`, `PASS_IF_EXISTS`, and `MAINTAINER_CANT_MODIFY`, these are
 treated as environment booleans. If they are defined in the environment, they trigger the
diff --git a/pull-request.py b/pull-request.py
index f95ad1d..98971ee 100755
--- a/pull-request.py
+++ b/pull-request.py
@@ -235,8 +235,7 @@ def find_pull_request(listing, source):
 
 
 def find_default_branch():
-    """Find default branch for a repo (only called if branch not provided)
-    """
+    """Find default branch for a repo (only called if branch not provided)"""
     response = requests.get(REPO_URL)
 
     # Case 1: 404 might need a token
@@ -283,7 +282,9 @@ def add_reviewers(entry, reviewers, team_reviewers):
 ################################################################################
 
 API_VERSION = "v3"
-BASE = "https://api.github.com"
+
+# Allow for a GitHub enterprise URL
+BASE = os.environ.get("GITHUB_API_URL") or "https://api.github.com"
 
 PR_TOKEN = os.environ.get("PULL_REQUEST_TOKEN") or get_envar("GITHUB_TOKEN")
 PR_REPO = os.environ.get("PULL_REQUEST_REPOSITORY") or get_envar("GITHUB_REPOSITORY")