diff --git a/build/print-workspace-status.py b/build/print-workspace-status.py
index 70e6e58..af62079 100755
--- a/build/print-workspace-status.py
+++ b/build/print-workspace-status.py
@@ -36,7 +36,8 @@
 
 # Git build tree status: clean or dirty.
 git_tree_state: str = "clean"
-if subprocess.call(["git", "status", "--porcelain"], stdout=subprocess.PIPE) == 0:
+git_status = subprocess.check_output(["git", "status", "--porcelain"])
+if git_status.decode().strip() != "":
     git_tree_state = "dirty"
 
 # Git commit hash.