diff --git a/conservancy_beancount/reconcile/statement_reconciler.py b/conservancy_beancount/reconcile/statement_reconciler.py
index 87865cc..904f101 100644
--- a/conservancy_beancount/reconcile/statement_reconciler.py
+++ b/conservancy_beancount/reconcile/statement_reconciler.py
@@ -702,9 +702,10 @@ def parse_repo_relative_path(path: str) -> str:
     if not os.path.exists(path):
         raise argparse.ArgumentTypeError(f'File {path} does not exist.')
     real_path = os.path.realpath(path)
-    repo = os.path.realpath(os.getenv('CONSERVANCY_REPOSITORY'))
-    if not repo:
-        raise argparse.ArgumentTypeError('$CONSERVANCY_REPOSITORY is not set.')
+    try:
+        repo = os.path.realpath(os.environ['CONSERVANCY_REPOSITORY'])
+    except KeyError:
+        raise argparse.ArgumentTypeError('$CONSERVANCY_REPOSITORY environment variable is not set.')
     if not real_path.startswith(repo):
         raise argparse.ArgumentTypeError(
             f'File {real_path} does not share a common prefix with $CONSERVANCY_REPOSITORY {repo}.'