diff --git a/Iceshrimp.Backend/Core/Federation/ActivityPub/MentionsResolver.cs b/Iceshrimp.Backend/Core/Federation/ActivityPub/MentionsResolver.cs
index deb69a85..79229006 100644
--- a/Iceshrimp.Backend/Core/Federation/ActivityPub/MentionsResolver.cs
+++ b/Iceshrimp.Backend/Core/Federation/ActivityPub/MentionsResolver.cs
@@ -5,6 +5,7 @@ using Iceshrimp.Backend.Core.Helpers.LibMfm.Parsing;
 using Iceshrimp.Backend.Core.Helpers.LibMfm.Serialization;
 using Microsoft.Extensions.Options;
 using Microsoft.FSharp.Collections;
+using Microsoft.FSharp.Core;
 using static Iceshrimp.Parsing.MfmNodeTypes;
 
 namespace Iceshrimp.Backend.Core.Federation.ActivityPub;
@@ -75,8 +76,10 @@ public class MentionsResolver(
 
 		if (resolvedUser != null)
 		{
-			return new MfmMentionNode($"@{resolvedUser.Username}@{resolvedUser.Host}",
-			                          resolvedUser.Username, resolvedUser.Host);
+			return resolvedUser.Host == null
+				? new MfmMentionNode($"@{resolvedUser.Username}", resolvedUser.Username, FSharpOption<string>.None)
+				: new MfmMentionNode($"@{resolvedUser.Username}@{resolvedUser.Host}", resolvedUser.Username,
+				                     FSharpOption<string>.Some(resolvedUser.Host));
 		}
 
 		return new MfmPlainNode($"@{node.Acct}");
diff --git a/Iceshrimp.Frontend/Components/Compose.razor b/Iceshrimp.Frontend/Components/Compose.razor
index 4a58f362..25f47d86 100644
--- a/Iceshrimp.Frontend/Components/Compose.razor
+++ b/Iceshrimp.Frontend/Components/Compose.razor
@@ -43,10 +43,12 @@
         }
         @if (NoteDraft.Cw != null)
         {
-            <input @bind="NoteDraft.Cw" class="input cw-field" placeholder="Content Warning" aria-label="content warning"/>
+            <input @bind="NoteDraft.Cw" class="input cw-field" placeholder="Content Warning"
+                   aria-label="content warning"/>
             <hr class="separator"/>
         }
-        <textarea @ref="Textarea" @bind="NoteDraft.Text" class="textarea" placeholder="@TextPlaceholder" rows="5" cols="35" autofocus="autofocus" aria-label="note text"></textarea>
+        <textarea @ref="Textarea" @bind="NoteDraft.Text" class="textarea" placeholder="@TextPlaceholder" rows="5"
+                  cols="35" autofocus="autofocus" aria-label="note text"></textarea>
         <div class="footer">
             <button class="btn" title="@Loc["Upload file"]" @onclick="OpenUpload" aria-label="upload">
                 <Icon Name="Icons.Upload" Size="1.3rem"></Icon>
@@ -54,7 +56,8 @@
             <button class="btn" title="@Loc["Content warning"]" @onclick="ToggleCw" aria-label="content warning">
                 <Icon Name="Icons.EyeSlash" Size="1.3rem"></Icon>
             </button>
-            <button @ref="EmojiButton" class="btn" title="@Loc["Emoji"]" @onclick="ToggleEmojiPicker" aria-label="emoji">
+            <button @ref="EmojiButton" class="btn" title="@Loc["Emoji"]" @onclick="ToggleEmojiPicker"
+                    aria-label="emoji">
                 <Icon Name="Icons.Smiley" Size="1.3rem"></Icon>
             </button>
             <div class="file-input">
@@ -201,7 +204,7 @@
         }
 
         var current  = $"@{SessionService.Current.Username}@{SessionService.Current.Host}";
-        var mfmNodes = Mfm.parse(noteBase.Text);
+        var mfmNodes = noteBase.Text != null ? Mfm.parse(noteBase.Text) : [];
         foreach (var node in mfmNodes)
         {
             if (node is MfmNodeTypes.MfmMentionNode mentionNode)
diff --git a/Iceshrimp.Parsing/Mfm.fs b/Iceshrimp.Parsing/Mfm.fs
index 30cacfb3..d72ce008 100644
--- a/Iceshrimp.Parsing/Mfm.fs
+++ b/Iceshrimp.Parsing/Mfm.fs
@@ -375,7 +375,7 @@ module private MfmParser =
         .>> clearParen
         >>= fun uri ->
             match Uri.TryCreate(uri, UriKind.Absolute) with
-            | true, finalUri ->
+            | true, NonNullQuick finalUri ->
                 match finalUri.Scheme with
                 | "http" -> preturn (MfmUrlNode(uri, false) :> MfmNode)
                 | "https" -> preturn (MfmUrlNode(uri, false) :> MfmNode)
@@ -388,7 +388,7 @@ module private MfmParser =
         >>. manyCharsTill anyChar (skipChar '>')
         >>= fun uri ->
             match Uri.TryCreate(uri, UriKind.Absolute) with
-            | true, finalUri ->
+            | true, NonNullQuick finalUri ->
                 match finalUri.Scheme with
                 | "http" -> preturn (MfmUrlNode(uri, true) :> MfmNode)
                 | "https" -> preturn (MfmUrlNode(uri, true) :> MfmNode)
@@ -406,7 +406,7 @@ module private MfmParser =
         .>> clearParen
         >>= fun ((silent, text), uri) ->
             match Uri.TryCreate(uri, UriKind.Absolute) with
-            | true, finalUri ->
+            | true, NonNullQuick finalUri ->
                 match finalUri.Scheme with
                 | "http" -> preturn (MfmLinkNode(uri, text, silent.IsSome) :> MfmNode)
                 | "https" -> preturn (MfmLinkNode(uri, text, silent.IsSome) :> MfmNode)