diff --git a/Libraries/LibWeb/DOM/PseudoElement.h b/Libraries/LibWeb/DOM/PseudoElement.h
index 8449a165740..9e977e47a0e 100644
--- a/Libraries/LibWeb/DOM/PseudoElement.h
+++ b/Libraries/LibWeb/DOM/PseudoElement.h
@@ -6,10 +6,12 @@
 
 #pragma once
 
+#include <AK/OwnPtr.h>
 #include <LibGC/CellAllocator.h>
 #include <LibJS/Heap/Cell.h>
 #include <LibWeb/CSS/StyleProperty.h>
 #include <LibWeb/Forward.h>
+#include <LibWeb/PixelUnits.h>
 #include <LibWeb/TreeNode.h>
 
 namespace Web::DOM {
diff --git a/Libraries/LibWeb/Forward.h b/Libraries/LibWeb/Forward.h
index 8cfb11e6fac..68c06207715 100644
--- a/Libraries/LibWeb/Forward.h
+++ b/Libraries/LibWeb/Forward.h
@@ -192,6 +192,7 @@ class BasicShapeStyleValue;
 class BorderImageSliceStyleValue;
 class BorderRadiusStyleValue;
 class CalculatedStyleValue;
+class CascadedProperties;
 class Clip;
 class ColorMixStyleValue;
 class ColorSchemeStyleValue;