diff --git a/bin/mcserv b/bin/mcserv
index 2871fe3..e64fb8c 100755
--- a/bin/mcserv
+++ b/bin/mcserv
@@ -25,21 +25,33 @@ error_usage() {
 }
 
 public_start() {
-    mcscreen -d -m -S "$1" \
-        "/srv/minecraft/bin/${1}"
+    if [ -n "$1" ]; then
+        mcscreen -d -m -S "$1" \
+            "/srv/minecraft/bin/${1}"
+    else
+        error_usage
+    fi
 }
 
 public_status() {
-    printf '\033[1m%s\033[0m : ' "$1"
-    if mcscreen -ls "$1" > /dev/null 2>&1; then
-        echo "en cours d'exécution"
+    if [ -n "$1" ]; then
+        printf '\033[1m%s\033[0m : ' "$1"
+        if mcscreen -ls "$1" > /dev/null 2>&1; then
+            echo "en cours d'exécution"
+        else
+            echo "non en cours d'exécution"
+        fi
     else
-        echo "non en cours d'exécution"
+        error_usage
     fi
 }
 
 public_stop() {
-    mcscreen -S "$1" -X stuff '^E^Ustop^M'
+    if [ -n "$1" ]; then
+        mcscreen -S "$1" -X stuff '^E^Ustop^M'
+    else
+        error_usage
+    fi
 }
 
 public_watch() {