diff --git a/src/BizHawk.Client.Common/movie/bk2/Bk2LogEntryGenerator.cs b/src/BizHawk.Client.Common/movie/bk2/Bk2LogEntryGenerator.cs
index 3dd2db5365..a170379680 100644
--- a/src/BizHawk.Client.Common/movie/bk2/Bk2LogEntryGenerator.cs
+++ b/src/BizHawk.Client.Common/movie/bk2/Bk2LogEntryGenerator.cs
@@ -42,7 +42,7 @@ namespace BizHawk.Client.Common
 			return sb.ToString();
 		}
 
-		public Dictionary<string, string> Map()
+		public IDictionary<string, string> Map()
 		{
 			var dict = new Dictionary<string, string>();
 			foreach (var group in _source.Definition.ControlsOrdered.Where(c => c.Any()))
diff --git a/src/BizHawk.Client.Common/movie/interfaces/ILogEntryGenerator.cs b/src/BizHawk.Client.Common/movie/interfaces/ILogEntryGenerator.cs
index c893431d43..c29ca3652e 100644
--- a/src/BizHawk.Client.Common/movie/interfaces/ILogEntryGenerator.cs
+++ b/src/BizHawk.Client.Common/movie/interfaces/ILogEntryGenerator.cs
@@ -23,7 +23,7 @@ namespace BizHawk.Client.Common
 		/// <summary>
 		/// Generates a dictionary of button names to their corresponding mnemonic values
 		/// </summary>
-		Dictionary<string, string> Map();
+		IDictionary<string, string> Map();
 
 		/// <summary>
 		/// Generates a display friendly version of the input log entry