diff --git a/RecrownedAthenaeum.ConsoleTools/NinePatchTools/NinePatchCommand.cs b/RecrownedAthenaeum.ConsoleTools/NinePatchTools/NinePatchCommand.cs
index d07960b..4e4b216 100644
--- a/RecrownedAthenaeum.ConsoleTools/NinePatchTools/NinePatchCommand.cs
+++ b/RecrownedAthenaeum.ConsoleTools/NinePatchTools/NinePatchCommand.cs
@@ -8,6 +8,11 @@ namespace RecrownedAthenaeum.Tools.NinePatchTools
 {
     public class NinePatchCommand : EngineCommand
     {
+        private enum SupportedExtensions
+        {
+            jpeg, jpg, png
+        }
+
         public NinePatchCommand() : base("9p", "ninepatch", "9patch")
         {
             help = "Generates a 9 patch file for a given image.";
@@ -41,6 +46,9 @@ namespace RecrownedAthenaeum.Tools.NinePatchTools
             NinePatchData npData = new NinePatchData(Path.GetFileName(imagePath), leftBound, rightBound, bottomBound, topBound);
             string serialized = JsonConvert.SerializeObject(npData, Formatting.Indented);
 
+            if (!File.Exists(imagePath)) throw new ArgumentException("Input file does not exist.");
+            SupportedExtensions extension;
+            if (!Enum.TryParse<SupportedExtensions>(Path.GetExtension(imagePath).ToLower().Substring(1), out extension)) throw new ArgumentException("Input file extension not supported.");
             using (StreamWriter stringWriter = new StreamWriter(outPath + ".9p"))
             {
                 stringWriter.WriteLine(serialized);