diff --git a/finish.sh b/finish.sh
index aa2e701..e2a5060 100644
--- a/finish.sh
+++ b/finish.sh
@@ -513,8 +513,9 @@ show_config() {
 }
 
 set_config() {
-    local key="$1" value="$2" config_file="$HOME/.finish/config"
+    local key="$1" value="$2" config_file="$HOME/.finish/config" lowercase_key
     key=$(echo "$key" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
+    lowercase_key=$(echo "$key" | tr '[:upper:]' '[:lower:]')
     key=$(echo "$key" | tr '[:lower:]' '[:upper:]' | sed 's/[^A-Z0-9]/_/g')
     if [ -z "$key" ]; then
         echo_error "SyntaxError: expected 'finish config set <key> <value>'"
@@ -524,7 +525,7 @@ set_config() {
         echo_error "Configuration file not found: $config_file. Run finish install."
         return
     fi
-    sed -i "s|^\($key:\).*|\1 $value|" "$config_file"
+    sed -i "s|^\($lowercase_key:\).*|\1 $value|" "$config_file"
     acsh_load_config
 }