diff --git a/launcher/src/main/java/com/skcraft/launcher/model/minecraft/GameArgument.java b/launcher/src/main/java/com/skcraft/launcher/model/minecraft/GameArgument.java
index bc4bfbd..5c4046d 100644
--- a/launcher/src/main/java/com/skcraft/launcher/model/minecraft/GameArgument.java
+++ b/launcher/src/main/java/com/skcraft/launcher/model/minecraft/GameArgument.java
@@ -4,9 +4,11 @@
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import com.google.common.base.Joiner;
 import com.google.common.collect.Lists;
 import com.skcraft.launcher.model.minecraft.mapper.ArgumentValueDeserializer;
+import com.skcraft.launcher.model.minecraft.mapper.ArgumentValueSerializer;
 import com.skcraft.launcher.util.Environment;
 import lombok.Data;
 import lombok.NoArgsConstructor;
@@ -19,6 +21,7 @@
 public class GameArgument {
 	@JsonProperty("value")
 	@JsonDeserialize(using = ArgumentValueDeserializer.class)
+	@JsonSerialize(using = ArgumentValueSerializer.class)
 	private List<String> values;
 	private List<Rule> rules;
 
diff --git a/launcher/src/main/java/com/skcraft/launcher/model/minecraft/mapper/ArgumentValueSerializer.java b/launcher/src/main/java/com/skcraft/launcher/model/minecraft/mapper/ArgumentValueSerializer.java
new file mode 100644
index 0000000..94b00b2
--- /dev/null
+++ b/launcher/src/main/java/com/skcraft/launcher/model/minecraft/mapper/ArgumentValueSerializer.java
@@ -0,0 +1,25 @@
+package com.skcraft.launcher.model.minecraft.mapper;
+
+import com.fasterxml.jackson.core.JsonGenerationException;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+import com.fasterxml.jackson.databind.type.TypeFactory;
+
+import java.io.IOException;
+import java.util.List;
+
+public class ArgumentValueSerializer extends StdSerializer<List<String>> {
+	protected ArgumentValueSerializer() {
+		super(TypeFactory.defaultInstance().constructCollectionType(List.class, String.class));
+	}
+
+	@Override
+	public void serialize(List<String> value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonGenerationException {
+		if (value.size() == 1) {
+			jgen.writeString(value.get(0));
+		} else {
+			provider.defaultSerializeValue(value, jgen);
+		}
+	}
+}