diff --git a/Userland/Libraries/LibWeb/CSS/UnicodeRange.h b/Userland/Libraries/LibWeb/CSS/UnicodeRange.h
index 74662dda13..6d8c82946c 100644
--- a/Userland/Libraries/LibWeb/CSS/UnicodeRange.h
+++ b/Userland/Libraries/LibWeb/CSS/UnicodeRange.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/Assertions.h>
+#include <AK/String.h>
 
 namespace Web::CSS {
 
diff --git a/Userland/Libraries/LibWeb/Forward.h b/Userland/Libraries/LibWeb/Forward.h
index 95173ca931..5595c9cb92 100644
--- a/Userland/Libraries/LibWeb/Forward.h
+++ b/Userland/Libraries/LibWeb/Forward.h
@@ -454,6 +454,7 @@ class URLSearchParamsIterator;
 }
 
 namespace Web::Bindings {
+class CallbackType;
 class LocationObject;
 class OptionConstructor;
 class RangePrototype;
diff --git a/Userland/Libraries/LibWeb/HTML/CrossOrigin/CrossOriginOpenerPolicy.h b/Userland/Libraries/LibWeb/HTML/CrossOrigin/CrossOriginOpenerPolicy.h
index d17f40f2a7..578ef45a68 100644
--- a/Userland/Libraries/LibWeb/HTML/CrossOrigin/CrossOriginOpenerPolicy.h
+++ b/Userland/Libraries/LibWeb/HTML/CrossOrigin/CrossOriginOpenerPolicy.h
@@ -6,6 +6,8 @@
 
 #pragma once
 
+#include <AK/String.h>
+
 namespace Web::HTML {
 
 // https://html.spec.whatwg.org/multipage/origin.html#cross-origin-opener-policy-value
diff --git a/Userland/Libraries/LibWeb/HTML/CrossOrigin/CrossOriginOpenerPolicyEnforcementResult.h b/Userland/Libraries/LibWeb/HTML/CrossOrigin/CrossOriginOpenerPolicyEnforcementResult.h
index 50e58875a9..607497412d 100644
--- a/Userland/Libraries/LibWeb/HTML/CrossOrigin/CrossOriginOpenerPolicyEnforcementResult.h
+++ b/Userland/Libraries/LibWeb/HTML/CrossOrigin/CrossOriginOpenerPolicyEnforcementResult.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/URL.h>
+#include <LibWeb/HTML/CrossOrigin/CrossOriginOpenerPolicy.h>
 #include <LibWeb/HTML/Origin.h>
 
 namespace Web::HTML {
diff --git a/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.h b/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.h
index fd400ea21e..d5255d3f2c 100644
--- a/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.h
+++ b/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.h
@@ -8,6 +8,7 @@
 
 #include <AK/Optional.h>
 #include <AK/String.h>
+#include <LibJS/Heap/GCPtr.h>
 #include <LibWeb/Forward.h>
 
 namespace Web::HTML {
diff --git a/Userland/Libraries/LibWeb/HTML/SandboxingFlagSet.h b/Userland/Libraries/LibWeb/HTML/SandboxingFlagSet.h
index 29ec4f7311..1e16261d8a 100644
--- a/Userland/Libraries/LibWeb/HTML/SandboxingFlagSet.h
+++ b/Userland/Libraries/LibWeb/HTML/SandboxingFlagSet.h
@@ -6,6 +6,8 @@
 
 #pragma once
 
+#include <AK/Types.h>
+
 namespace Web::HTML {
 
 // https://html.spec.whatwg.org/multipage/origin.html#sandboxing-flag-set
diff --git a/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.h b/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.h
index 859babd244..504459bf66 100644
--- a/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.h
+++ b/Userland/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.h
@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <LibJS/Heap/Handle.h>
 #include <LibWeb/Bindings/PlatformObject.h>
 
 namespace Web::IntersectionObserver {
diff --git a/Userland/Libraries/LibWeb/Layout/InlineLevelIterator.h b/Userland/Libraries/LibWeb/Layout/InlineLevelIterator.h
index 23bfcb9a72..e96dc9babf 100644
--- a/Userland/Libraries/LibWeb/Layout/InlineLevelIterator.h
+++ b/Userland/Libraries/LibWeb/Layout/InlineLevelIterator.h
@@ -9,6 +9,7 @@
 #include <AK/Noncopyable.h>
 #include <LibWeb/Layout/BlockContainer.h>
 #include <LibWeb/Layout/InlineNode.h>
+#include <LibWeb/Layout/LayoutState.h>
 #include <LibWeb/Layout/TextNode.h>
 
 namespace Web::Layout {