diff --git a/docs/release-notes.md b/docs/release-notes.md
index d1a78aaa..e4ae720d 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -27,9 +27,10 @@
   * Fixed console command input not saved to the log.
   * Fixed `helper.ModRegistry.GetApi` interface validation errors not mentioning which interface caused the issue.
   * **Breaking changes** (see [migration guide](https://stardewvalleywiki.com/Modding:Migrate_to_Stardew_Valley_1.3)):
-     * dropped some deprecated APIs;
-     * `LocationEvents` have been rewritten (see above);
-     * mods can't intercept chatbox input, including the game's hotkeys to toggle the chatbox (default `T` and `?`).
+     * Dropped some deprecated APIs.
+     * `LocationEvents` have been rewritten (see above).
+     * Mods can't intercept chatbox input, including the game's hotkeys to toggle the chatbox (default `T` and `?`).
+     * Mod IDs should only contain letters, numbers, hyphens, dots, and underscores (so they can be safely used in many contexts like URLs); this restriction is now enforced.
 
 * In console commands:
   * Added `player_add name`, which lets you add items to your inventory by name instead of ID.
diff --git a/src/SMAPI/Framework/ModLoading/ModResolver.cs b/src/SMAPI/Framework/ModLoading/ModResolver.cs
index a9896278..cec37fca 100644
--- a/src/SMAPI/Framework/ModLoading/ModResolver.cs
+++ b/src/SMAPI/Framework/ModLoading/ModResolver.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text.RegularExpressions;
 using StardewModdingAPI.Framework.Exceptions;
 using StardewModdingAPI.Framework.ModData;
 using StardewModdingAPI.Framework.Models;
@@ -194,8 +195,15 @@ namespace StardewModdingAPI.Framework.ModLoading
                         missingFields.Add(nameof(IManifest.UniqueID));
 
                     if (missingFields.Any())
+                    {
                         mod.SetStatus(ModMetadataStatus.Failed, $"its manifest is missing required fields ({string.Join(", ", missingFields)}).");
+                        continue;
+                    }
                 }
+
+                // validate ID format
+                if (Regex.IsMatch(mod.Manifest.UniqueID, "[^a-z0-9_.-]", RegexOptions.IgnoreCase))
+                    mod.SetStatus(ModMetadataStatus.Failed, "its manifest specifies an invalid ID (IDs must only contain letters, numbers, underscores, periods, or hyphens).");
             }
 
             // validate IDs are unique