diff --git a/ArcFormats/ImageDRG.cs b/ArcFormats/ImageDRG.cs
index 8c92c4f3..8d99b33b 100644
--- a/ArcFormats/ImageDRG.cs
+++ b/ArcFormats/ImageDRG.cs
@@ -151,7 +151,7 @@ namespace GameRes.Formats.DRS
                     src_offset = out_pos - 3 * input.ReadByte ();
                     if (count < 0 || count > pixel_count || src_offset < 0 || src_offset == out_pos)
                         return null;
-                    CopyOverlapped (output, src_offset, out_pos, count);
+                    Binary.CopyOverlapped (output, src_offset, out_pos, count);
                     out_pos += count;
                     pixel_count -= count;
                     break;
@@ -163,7 +163,7 @@ namespace GameRes.Formats.DRS
                         src_offset = out_pos - 3 * (off_hi << 8 | off_lo);
                         if (count < 0 || count > pixel_count || src_offset < 0 || src_offset == out_pos)
                             return null;
-                        CopyOverlapped (output, src_offset, out_pos, count);
+                        Binary.CopyOverlapped (output, src_offset, out_pos, count);
                         out_pos += count;
                         pixel_count -= count;
                         break;
@@ -205,20 +205,6 @@ namespace GameRes.Formats.DRS
             return output;
         }
 
-        static internal void CopyOverlapped (byte[] data, int src, int dst, int count)
-        {
-            int preceding = dst-src;
-            while (count > 0)
-            {
-                if (preceding > count)
-                    preceding = count;
-                Array.Copy (data, src, data, dst, preceding);
-                src = dst;
-                dst += preceding;
-                count -= preceding;
-            }
-        }
-
         internal class Writer : IDisposable
         {
             BinaryWriter    m_out;
diff --git a/ArcFormats/ImageRCT.cs b/ArcFormats/ImageRCT.cs
index 3ef2bbcd..27b4545f 100644
--- a/ArcFormats/ImageRCT.cs
+++ b/ArcFormats/ImageRCT.cs
@@ -399,26 +399,12 @@ namespace GameRes.Formats.Majiro
                         shift *= 3;
                         if (shift >= 0 || data_pos+shift < 0)
                             throw new InvalidFormatException();
-                        CopyOverlapped (m_data, data_pos+shift, data_pos, count);
+                        Binary.CopyOverlapped (m_data, data_pos+shift, data_pos, count);
                         data_pos += count;
                     }
                 }
             }
 
-            static internal void CopyOverlapped (byte[] data, int src, int dst, int count)
-            {
-                int preceding = dst-src;
-                while (count > 0)
-                {
-                    if (preceding > count)
-                        preceding = count;
-                    Array.Copy (data, src, data, dst, preceding);
-                    src = dst;
-                    dst += preceding;
-                    count -= preceding;
-                }
-            }
-
             #region IDisposable Members
             bool disposed = false;
 
@@ -575,7 +561,7 @@ namespace GameRes.Formats.Majiro
                         shift -= shift_row;
                         if (shift >= 0 || data_pos+shift < 0)
                             throw new InvalidFormatException();
-                        RctFormat.Reader.CopyOverlapped (m_data, data_pos+shift, data_pos, count);
+                        Binary.CopyOverlapped (m_data, data_pos+shift, data_pos, count);
                         data_pos += count;
                     }
                 }
diff --git a/GameRes/Utility.cs b/GameRes/Utility.cs
index 1341fb77..072dea93 100644
--- a/GameRes/Utility.cs
+++ b/GameRes/Utility.cs
@@ -69,6 +69,20 @@ namespace GameRes.Utility
                     return false;
             return true;
         }
+
+        public static void CopyOverlapped (byte[] data, int src, int dst, int count)
+        {
+            int preceding = dst-src;
+            while (count > 0)
+            {
+                if (preceding > count)
+                    preceding = count;
+                System.Array.Copy (data, src, data, dst, preceding);
+                src = dst;
+                dst += preceding;
+                count -= preceding;
+            }
+        }
     }
 
     public static class LittleEndian