diff --git a/deploy.py b/deploy.py
index c698264..cb0bcfb 100755
--- a/deploy.py
+++ b/deploy.py
@@ -523,7 +523,7 @@ class OpenSKInstaller:
     if self.args.programmer == "pyocd":
       self.checked_command([
           "pyocd", "erase", "--target={}".format(board_props.pyocd_target),
-          "--sector {}+{}".format(board_props.storage_address,
+          "--sector={}+{}".format(board_props.storage_address,
                                   board_props.storage_size)
       ])
       return 0