diff --git a/Userland/Libraries/LibWeb/CMakeLists.txt b/Userland/Libraries/LibWeb/CMakeLists.txt
index 48d09efd93..0633930fea 100644
--- a/Userland/Libraries/LibWeb/CMakeLists.txt
+++ b/Userland/Libraries/LibWeb/CMakeLists.txt
@@ -276,6 +276,7 @@ set(SOURCES
     Infra/ByteSequences.cpp
     Infra/JSON.cpp
     IntersectionObserver/IntersectionObserver.cpp
+    Layout/AvailableSpace.cpp
     Layout/BlockContainer.cpp
     Layout/BlockFormattingContext.cpp
     Layout/Box.cpp