diff --git a/msm b/msm
index 3334d6f..491adef 100755
--- a/msm
+++ b/msm
@@ -164,13 +164,14 @@ server_delete() {
 server_rename() {
 	if is_valid_name "$1"; then
 		if [[ -e "$SERVER_STORAGE_PATH/$1" ]]; then
-			# If the server name is valid,
-			# and there is no other server with the name $1
+			# If the server name is valid and exists
 		
 			# TODO: Check that the server is not running first, return if it is
 		
 			if is_valid_name "$2"; then
+				# If the server name is valid
 				if [[ -e "$SERVER_STORAGE_PATH/$2" ]]; then
+					# and there is not already a server with the name $2
 					echo "Could not be renamed, there is already a server with the name \"$2\"."
 					return 1
 				else
@@ -334,6 +335,36 @@ jargroup_delete() {
 	fi
 }
 
+# Renames an existing jargroup
+# $1: The name of the existing jargroup
+# $2: The new name
+jargroup_rename() {
+	if is_valid_name "$1"; then
+		if [[ -e "$JAR_STORAGE_PATH/$1" ]]; then
+			# If the jar group name is valid,
+			# and there is no other jar group with the name $1
+		
+			if is_valid_name "$2"; then
+				if [[ -e "$JAR_STORAGE_PATH/$2" ]]; then
+					echo "Could not be renamed, there is already a jar group with the name \"$2\"."
+					return 1
+				else
+					# TODO: Update any symbolic links which point to a jar in this directory
+					as_user "mv '$JAR_STORAGE_PATH/$1' '$JAR_STORAGE_PATH/$2'"
+					echo "Renamed jar group \"$1\" to \"$2\"."
+				fi
+			else
+				return 1
+			fi
+		else
+			echo "There is no jar group with the name \"$1\"."
+			return 1
+		fi
+	else
+		return 1
+	fi
+}
+
 
 ### Script Options
 
@@ -408,6 +439,11 @@ case "$1" in
 					
 				;;
 			rename)
+				if [ -z "$3" ] || [ -z "$4" ]; then
+					echo "Invalid command."
+				else
+					jargroup_rename $3 $4
+				fi
 				;;
 			changetarget)
 				if [ -z "$3" ] || [ -z "$4" ]; then