diff --git a/Assets/Cryville/Common/Pdt/PdtInternalType.cs b/Assets/Cryville/Common/Pdt/PdtInternalType.cs
index 51ede3f..4cca633 100644
--- a/Assets/Cryville/Common/Pdt/PdtInternalType.cs
+++ b/Assets/Cryville/Common/Pdt/PdtInternalType.cs
@@ -3,26 +3,26 @@
 	/// The identifiers of the internal types of PDT.
 	/// </summary>
 	public static class PdtInternalType {
-		internal readonly static int Error = "error".GetHashCode();
+		internal readonly static int Error = 0x00525245;
 		/// <summary>
 		/// Array of a same variable-length type, with a suffix indicating the element count and the element type.
 		/// </summary>
-		public readonly static int Array = "array".GetHashCode();
+		public readonly static int Array = 0x00525241;
 		/// <summary>
 		/// IEEE 754 32-bit floating-point number.
 		/// </summary>
-		public readonly static int Number = "number".GetHashCode();
+		public readonly static int Number = 0x004d554e;
 		/// <summary>
 		/// A sequence of UTF-16 code units, with a prefix indicating the number of the code units.
 		/// </summary>
-		public readonly static int String = "string".GetHashCode();
+		public readonly static int String = 0x00525453;
 		/// <summary>
 		/// A sequence of UTF-16 code units, with a prefix indicating the number of the code units, representing the name of an undefined variable.
 		/// </summary>
-		public readonly static int Undefined = "undefined".GetHashCode();
+		public readonly static int Undefined = 0x00444e55;
 		/// <summary>
 		/// Vector of a same constant-length type, with a suffix indicating the element type.
 		/// </summary>
-		public readonly static int Vector = "vector".GetHashCode();
+		public readonly static int Vector = 0x00434556;
 	}
 }