diff --git a/Libraries/LibWeb/CMakeLists.txt b/Libraries/LibWeb/CMakeLists.txt
index 4fd706ca08b..827d64151bd 100644
--- a/Libraries/LibWeb/CMakeLists.txt
+++ b/Libraries/LibWeb/CMakeLists.txt
@@ -39,6 +39,7 @@ set(SOURCES
     ContentSecurityPolicy/Directives/Directive.cpp
     ContentSecurityPolicy/Directives/DirectiveFactory.cpp
     ContentSecurityPolicy/Directives/DirectiveOperations.cpp
+    ContentSecurityPolicy/Directives/KeywordSources.cpp
     ContentSecurityPolicy/Directives/Names.cpp
     ContentSecurityPolicy/Directives/SerializedDirective.cpp
     ContentSecurityPolicy/Policy.cpp
diff --git a/Libraries/LibWeb/ContentSecurityPolicy/Directives/KeywordSources.cpp b/Libraries/LibWeb/ContentSecurityPolicy/Directives/KeywordSources.cpp
new file mode 100644
index 00000000000..5ec0532e333
--- /dev/null
+++ b/Libraries/LibWeb/ContentSecurityPolicy/Directives/KeywordSources.cpp
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2025, Luke Wilde <luke@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/ContentSecurityPolicy/Directives/KeywordSources.h>
+
+namespace Web::ContentSecurityPolicy::Directives::KeywordSources {
+
+#define __ENUMERATE_KEYWORD_SOURCE(name, value) \
+    FlyString name = value##_fly_string;
+ENUMERATE_KEYWORD_SOURCES
+#undef __ENUMERATE_KEYWORD_SOURCE
+
+}
diff --git a/Libraries/LibWeb/ContentSecurityPolicy/Directives/KeywordSources.h b/Libraries/LibWeb/ContentSecurityPolicy/Directives/KeywordSources.h
new file mode 100644
index 00000000000..ab753f318ed
--- /dev/null
+++ b/Libraries/LibWeb/ContentSecurityPolicy/Directives/KeywordSources.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2025, Luke Wilde <luke@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/FlyString.h>
+
+namespace Web::ContentSecurityPolicy::Directives::KeywordSources {
+
+// https://w3c.github.io/webappsec-csp/#grammardef-keyword-source
+#define ENUMERATE_KEYWORD_SOURCES                                                \
+    __ENUMERATE_KEYWORD_SOURCE(Self, "'self'")                                   \
+    __ENUMERATE_KEYWORD_SOURCE(UnsafeInline, "'unsafe-inline'")                  \
+    __ENUMERATE_KEYWORD_SOURCE(UnsafeEval, "'unsafe-eval'")                      \
+    __ENUMERATE_KEYWORD_SOURCE(StrictDynamic, "'strict-dynamic'")                \
+    __ENUMERATE_KEYWORD_SOURCE(UnsafeHashes, "'unsafe-hashes'")                  \
+    __ENUMERATE_KEYWORD_SOURCE(ReportSample, "'report-sample'")                  \
+    __ENUMERATE_KEYWORD_SOURCE(UnsafeAllowRedirects, "'unsafe-allow-redirects'") \
+    __ENUMERATE_KEYWORD_SOURCE(WasmUnsafeEval, "'wasm-unsafe-eval'")
+
+#define __ENUMERATE_KEYWORD_SOURCE(name, value) extern FlyString name;
+ENUMERATE_KEYWORD_SOURCES
+#undef __ENUMERATE_KEYWORD_SOURCE
+
+}
diff --git a/Libraries/LibWeb/ContentSecurityPolicy/Directives/Names.h b/Libraries/LibWeb/ContentSecurityPolicy/Directives/Names.h
index ee26d3386f9..8022bcfd372 100644
--- a/Libraries/LibWeb/ContentSecurityPolicy/Directives/Names.h
+++ b/Libraries/LibWeb/ContentSecurityPolicy/Directives/Names.h
@@ -39,6 +39,4 @@ namespace Web::ContentSecurityPolicy::Directives::Names {
 ENUMERATE_DIRECTIVE_NAMES
 #undef __ENUMERATE_DIRECTIVE_NAME
 
-void initialize_strings();
-
 }