diff --git a/src/addoncreator/Addon/AddonFile.cs b/src/addoncreator/Addon/AddonFile.cs
index 8bf5736..25474d0 100644
--- a/src/addoncreator/Addon/AddonFile.cs
+++ b/src/addoncreator/Addon/AddonFile.cs
@@ -184,8 +184,9 @@ namespace GarrysMod.AddonCreator.Addon
                     // long-compatible file reading
                     for (long i = 0; i < fileSize; i += int.MaxValue)
                     {
-                        var tempContent = sr.ReadBytes((int) Math.Min(int.MaxValue, fileSize));
-                        tempContent.CopyTo(fileContent, i);
+                        sr
+                            .ReadBytes((int) Math.Min(int.MaxValue, fileSize))
+                            .CopyTo(fileContent, i);
                     }
 
                     // CRC check for this file
diff --git a/src/addoncreator/Addon/AddonFileInfo.cs b/src/addoncreator/Addon/AddonFileInfo.cs
index 1354631..d14d26d 100644
--- a/src/addoncreator/Addon/AddonFileInfo.cs
+++ b/src/addoncreator/Addon/AddonFileInfo.cs
@@ -12,7 +12,7 @@ namespace GarrysMod.AddonCreator.Addon
         /// </summary>
         public virtual long Size
         {
-            get { return _size.HasValue ? _size.Value : (_size = GetContents().Length).Value; }
+            get { lock(this) return _size.HasValue ? _size.Value : (_size = GetContents().Length).Value; }
         }
 
         /// <summary>
@@ -20,7 +20,7 @@ namespace GarrysMod.AddonCreator.Addon
         /// </summary>
         public virtual int Crc32Hash
         {
-            get { return _hash.HasValue ? _hash.Value : (_hash = Crc32.Compute(GetContents())).Value; }
+            get { lock (this) return _hash.HasValue ? _hash.Value : (_hash = Crc32.Compute(GetContents())).Value; }
         }
 
         /// <summary>