diff --git a/dvc/command/diff.py b/dvc/command/diff.py
index e23fef94f..68899bb86 100644
--- a/dvc/command/diff.py
+++ b/dvc/command/diff.py
@@ -134,7 +134,7 @@ def add_parser(subparsers, parent_parser):
         "a_ref",
         help=(
             "Git reference to the older version to compare "
-            "(defaults to `HEAD`)"
+            "(defaults to HEAD)"
         ),
         nargs="?",
         default="HEAD",
diff --git a/dvc/command/metrics.py b/dvc/command/metrics.py
index e6d92b739..77d28bbf0 100644
--- a/dvc/command/metrics.py
+++ b/dvc/command/metrics.py
@@ -287,7 +287,7 @@ def add_parser(subparsers, parent_parser):
         nargs="?",
         help=(
             "Git reference to the older version to compare "
-            "(defaults to `HEAD`)"
+            "(defaults to HEAD)"
         ),
     )
     metrics_diff_parser.add_argument(