diff --git a/RELEASE.md b/RELEASE.md
new file mode 100644
index 0000000..23f7c38
--- /dev/null
+++ b/RELEASE.md
@@ -0,0 +1,3 @@
+Release type: patch
+
+Fix `vf upgrade` error related to `sed`
diff --git a/virtualfish/virtual.fish b/virtualfish/virtual.fish
index 58d8626..c6bcc1c 100644
--- a/virtualfish/virtual.fish
+++ b/virtualfish/virtual.fish
@@ -620,7 +620,7 @@ function __vf_upgrade --description "Upgrade virtualenv(s) to newer Python versi
                 if [ -L "$venv_path/bin/python$old_py_mv" ]; command rm "$venv_path/bin/python$old_py_mv"; end
                 command ln -s "$python$new_py_mv" "$venv_path/bin/python$new_py_mv"
                 if test -f "$venv_path/pyvenv.cfg"
-                    command sed -i '' -e "s/$old_py_fv/$new_py_fv/g" "$venv_path/pyvenv.cfg"
+                    command sed -i -e "s/$old_py_fv/$new_py_fv/g" "$venv_path/pyvenv.cfg"
                 end
                 # Clear caches
                 command find "$venv_path" -name "__pycache__" -type d -print0|xargs -0 rm -r --