diff --git a/Userland/DevTools/Playground/CMakeLists.txt b/Userland/DevTools/Playground/CMakeLists.txt
index 6fa9f90b699..8b8a2604ebb 100644
--- a/Userland/DevTools/Playground/CMakeLists.txt
+++ b/Userland/DevTools/Playground/CMakeLists.txt
@@ -6,7 +6,6 @@ serenity_component(
 
 set(SOURCES
     main.cpp
-    GMLAutocompleteProvider.cpp
 )
 
 serenity_app(Playground ICON app-playground)
diff --git a/Userland/DevTools/Playground/main.cpp b/Userland/DevTools/Playground/main.cpp
index 7e0bd30e3d5..e139e3c6137 100644
--- a/Userland/DevTools/Playground/main.cpp
+++ b/Userland/DevTools/Playground/main.cpp
@@ -4,13 +4,13 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include "GMLAutocompleteProvider.h"
 #include <AK/URL.h>
 #include <LibCore/ArgsParser.h>
 #include <LibCore/File.h>
 #include <LibDesktop/Launcher.h>
 #include <LibGUI/Application.h>
 #include <LibGUI/FilePicker.h>
+#include <LibGUI/GMLAutocompleteProvider.h>
 #include <LibGUI/GMLFormatter.h>
 #include <LibGUI/GMLLexer.h>
 #include <LibGUI/GMLSyntaxHighlighter.h>
@@ -102,7 +102,7 @@ int main(int argc, char** argv)
     auto& preview = splitter.add<GUI::Frame>();
 
     editor.set_syntax_highlighter(make<GUI::GMLSyntaxHighlighter>());
-    editor.set_autocomplete_provider(make<GMLAutocompleteProvider>());
+    editor.set_autocomplete_provider(make<GUI::GMLAutocompleteProvider>());
     editor.set_should_autocomplete_automatically(true);
     editor.set_automatic_indentation_enabled(true);
 
diff --git a/Userland/Libraries/LibGUI/CMakeLists.txt b/Userland/Libraries/LibGUI/CMakeLists.txt
index 7f6cf35750f..62a0a424577 100644
--- a/Userland/Libraries/LibGUI/CMakeLists.txt
+++ b/Userland/Libraries/LibGUI/CMakeLists.txt
@@ -39,6 +39,7 @@ set(SOURCES
     FontPicker.cpp
     FontPickerDialogGML.h
     Frame.cpp
+    GMLAutocompleteProvider.cpp
     GMLFormatter.cpp
     GMLLexer.cpp
     GMLParser.cpp
diff --git a/Userland/DevTools/Playground/GMLAutocompleteProvider.cpp b/Userland/Libraries/LibGUI/GMLAutocompleteProvider.cpp
similarity index 99%
rename from Userland/DevTools/Playground/GMLAutocompleteProvider.cpp
rename to Userland/Libraries/LibGUI/GMLAutocompleteProvider.cpp
index 150f619b929..2b74356de97 100644
--- a/Userland/DevTools/Playground/GMLAutocompleteProvider.cpp
+++ b/Userland/Libraries/LibGUI/GMLAutocompleteProvider.cpp
@@ -5,8 +5,10 @@
  */
 
 #include "GMLAutocompleteProvider.h"
+#include "GMLLexer.h"
 #include <AK/QuickSort.h>
-#include <LibGUI/GMLLexer.h>
+
+namespace GUI {
 
 void GMLAutocompleteProvider::provide_completions(Function<void(Vector<Entry>)> callback)
 {
@@ -207,3 +209,5 @@ void GMLAutocompleteProvider::provide_completions(Function<void(Vector<Entry>)>
 
     callback(move(entries));
 }
+
+}
diff --git a/Userland/DevTools/Playground/GMLAutocompleteProvider.h b/Userland/Libraries/LibGUI/GMLAutocompleteProvider.h
similarity index 91%
rename from Userland/DevTools/Playground/GMLAutocompleteProvider.h
rename to Userland/Libraries/LibGUI/GMLAutocompleteProvider.h
index f6aaf21ed05..b08e30db518 100644
--- a/Userland/DevTools/Playground/GMLAutocompleteProvider.h
+++ b/Userland/Libraries/LibGUI/GMLAutocompleteProvider.h
@@ -6,7 +6,9 @@
 
 #pragma once
 
-#include <LibGUI/AutocompleteProvider.h>
+#include "AutocompleteProvider.h"
+
+namespace GUI {
 
 class GMLAutocompleteProvider final : public virtual GUI::AutocompleteProvider {
 public:
@@ -21,3 +23,5 @@ private:
 
     virtual void provide_completions(Function<void(Vector<Entry>)> callback) override;
 };
+
+}