diff --git a/src/main/java/org/libvirt/qemu/QemuCommand.java b/src/main/java/org/libvirt/qemu/QemuCommand.java
index 975b826..4b4deb2 100644
--- a/src/main/java/org/libvirt/qemu/QemuCommand.java
+++ b/src/main/java/org/libvirt/qemu/QemuCommand.java
@@ -1,31 +1,86 @@
 package org.libvirt.qemu;
 
+import java.lang.IllegalArgumentException;
+
 public class QemuCommand {
-    String command;
+
+    public enum Command {
+
+        GUEST_INFO("guest-info", false),
+        GUEST_SYNC_DELIMITED("guest-sync-delimited", true),
+        GUEST_SYNC("guest-sync", true),
+        GUEST_PING("guest-ping", false),
+        GUEST_GET_TIME("guest-get-time", false),
+        GUEST_SET_TIME("guest-set-time", true),
+        GUEST_SHUTDOWN("guest-shutdown", false),
+        GUEST_FILE_OPEN("guest-file-open", true),
+        GUEST_FILE_CLOSE("guest-file-close", true),
+        GUEST_FILE_READ("guest-file-read", true),
+        GUEST_FILE_WRITE("guest-file-write", true),
+        GUEST_FILE_SEEK("guest-file-seek", true),
+        GUEST_FILE_FLUSH("guest-file-flush", true),
+        GUEST_FSFREEZE_STATUS("guest-fsfreeze-status", false),
+        GUEST_FSFREEZE_FREEZE("guest-fsfreeze-freeze", false),
+        GUEST_FSFREEZE_LIST("guest-fsfreeze-freeze-list", true),
+        GUEST_FSFREEZE_THAW("guest-fsfreeze-thaw", false),
+        GUEST_FSTRIM("guest-fstrim", true),
+        GUEST_SUSPEND_DISK("guest-suspend-disk", false),
+        GUEST_SUSPEND_RAM("guest-suspend-ram", false),
+        GUEST_SUSPEND_HYBRID("guest-suspend-hybrid", false),
+        GUEST_GET_NETWORK_INTERFACES("guest-network-get-interfaces", false),
+        GUEST_GET_VCPUS("guest-get-vcpus", false),
+        GUEST_SET_VCPUS("guest-set-vcpus", true),
+        GUEST_GET_FSINFO("guest-get-fsinfo", false),
+        GUEST_SET_USER_PASSWORD("guest-set-user-password", true),
+        GUEST_GET_MEMORY_BLOCKS("guest-get-memory-blocks", false),
+        GUEST_SET_MEMORY_BLOCKS("guest-set-memory-blocks", true),
+        GUEST_GET_MEMORY_BLOCK_INFO("guest-get-memory-block-info", false),
+        GUEST_EXEC_STATUS("guest-exec-status", false),
+        GUEST_EXEC("guest-exec", true);
+
+        private final String command;
+        private final Boolean requiresArguments;
+
+        Command(String command, Boolean requiresArguments) {
+            this.command = command;
+            this.requiresArguments = requiresArguments;
+        }
+
+        private String getCommand() {
+            return command;
+        }
+
+        private Boolean requiresArguments() {
+            return requiresArguments;
+        }
+    }
+
+    Command command;
     String arguments;
 
-    public static QemuCommand create(String cmd) {
-        return new QemuCommand(cmd);
+    public static QemuCommand create(Command cmd) {
+        return new QemuCommand(cmd, null);
     }
 
-    public static QemuCommand create(String cmd, String args) {
+    public static QemuCommand create(Command cmd, String args) {
         return new QemuCommand(cmd, args);
     }
 
-    private QemuCommand(String command, String arguments) {
+    private QemuCommand(Command command, String arguments) {
         this.command = command;
-        this.arguments = arguments;
-    }
 
-    private QemuCommand(String command) {
-        this.command = command;
+        if (command.requiresArguments() && arguments == null) {
+            throw new IllegalArgumentException(command.getCommand() + " requires a argument");
+        }
+
+        this.arguments = arguments;
     }
 
     public String toString() {
         String json = "";
 
         json += "{";
-        json += "\"execute\": \"" + command + "\"";
+        json += "\"execute\": \"" + command.getCommand() + "\"";
 
         if (arguments != null && arguments.length() > 0) {
             json += "\"arguments\": " + arguments + "\"";
diff --git a/src/test/java/org/libvirt/qemu/TestQemuCommand.java b/src/test/java/org/libvirt/qemu/TestQemuCommand.java
index 58b6ccb..7fa415a 100644
--- a/src/test/java/org/libvirt/qemu/TestQemuCommand.java
+++ b/src/test/java/org/libvirt/qemu/TestQemuCommand.java
@@ -5,7 +5,7 @@
 public final class TestQemuCommand extends TestCase {
 
     public void testCommandWithoutArguments() {
-        QemuCommand command = QemuCommand.create("guest-info");
+        QemuCommand command = QemuCommand.create(QemuCommand.Command.GUEST_INFO);
         assertEquals("{\"execute\": \"guest-info\"}", command.toString());
     }
 }