diff --git a/OpenRA.FileFormats/FileFormats/CRC32.cs b/OpenRA.FileFormats/FileFormats/CRC32.cs
index 22fd2077c5..1bdbe833e9 100644
--- a/OpenRA.FileFormats/FileFormats/CRC32.cs
+++ b/OpenRA.FileFormats/FileFormats/CRC32.cs
@@ -96,7 +96,7 @@ namespace OpenRA.FileFormats
 		/// <returns>
 		/// The calculated checksum.
 		/// </returns>
-		public static uint Calculate(byte[] data, uint polynomal = 0xFFFFFFFF)
+		public static uint Calculate(byte[] data, uint polynomal)
 		{
 			uint crc = polynomal;
 			for (int i = 0; i < data.Length; i++)
@@ -104,6 +104,10 @@ namespace OpenRA.FileFormats
 			crc ^= polynomal;
 			return crc;
 		}
+		public static uint Calculate(byte[] data)
+		{
+			return Calculate(data, 0xFFFFFFFF);
+		}
 
 		/// <summary>
 		/// A fast (native) CRC32 implementation that can be used on a pinned byte array using
@@ -113,7 +117,7 @@ namespace OpenRA.FileFormats
 		/// <param name="len">		The length of the data data.</param>
 		/// <param name="polynomal">The polynomal to xor with.</param>
 		/// <returns>The calculated checksum.</returns>
-		public static unsafe uint Calculate(byte* data, uint len, uint polynomal = 0xFFFFFFFF)
+		public static unsafe uint Calculate(byte* data, uint len, uint polynomal)
 		{
 			uint crc = polynomal;
 			for (int i = 0; i < len; i++)
@@ -121,5 +125,9 @@ namespace OpenRA.FileFormats
 			crc ^= polynomal;
 			return crc;
 		}
+		public static unsafe uint Calculate(byte* data, uint len)
+		{
+			return Calculate(data, len, 0xFFFFFFFF);
+		}
 	}
 }
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