diff --git a/docs/release-notes.md b/docs/release-notes.md
index c247a9d5..014e8814 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -11,6 +11,7 @@
 * For players:
   * Added config options to override the mod load order, for the rare cases where that's needed (thanks to Shockah!).
   * Added config option to disable console input, which may reduce CPU usage on some Linux systems.
+  * Set the max game version to 1.5.6 (since 1.6 will need a SMAPI update).
 
 * For mod authors:
   * Optimized asset name comparisons (thanks to atravita!).
diff --git a/src/SMAPI/Constants.cs b/src/SMAPI/Constants.cs
index 77900ca6..222e5276 100644
--- a/src/SMAPI/Constants.cs
+++ b/src/SMAPI/Constants.cs
@@ -71,7 +71,7 @@ namespace StardewModdingAPI
         public static ISemanticVersion MinimumGameVersion { get; } = new GameVersion("1.5.6");
 
         /// <summary>The maximum supported version of Stardew Valley, if any.</summary>
-        public static ISemanticVersion? MaximumGameVersion { get; } = null;
+        public static ISemanticVersion? MaximumGameVersion { get; } = new GameVersion("1.5.6");
 
         /// <summary>The target game platform.</summary>
         public static GamePlatform TargetPlatform { get; } = EarlyConstants.Platform;