diff --git a/AK/HashMap.h b/AK/HashMap.h
index 4d4cdc516a9..9c9b9d972a2 100644
--- a/AK/HashMap.h
+++ b/AK/HashMap.h
@@ -9,13 +9,7 @@
 #include <AK/HashTable.h>
 #include <AK/Optional.h>
 #include <AK/Vector.h>
-
-// NOTE: We can't include <initializer_list> during the toolchain bootstrap,
-//       since it's part of libstdc++, and libstdc++ depends on LibC.
-//       For this reason, we don't support HashMap(initializer_list) in LibC.
-#ifndef SERENITY_LIBC_BUILD
-#    include <initializer_list>
-#endif
+#include <initializer_list>
 
 namespace AK {
 
@@ -38,14 +32,12 @@ public:
 
     HashMap() = default;
 
-#ifndef SERENITY_LIBC_BUILD
     HashMap(std::initializer_list<Entry> list)
     {
         ensure_capacity(list.size());
         for (auto& item : list)
             set(item.key, item.value);
     }
-#endif
 
     [[nodiscard]] bool is_empty() const
     {
diff --git a/AK/Vector.h b/AK/Vector.h
index 743d7b6a888..33908c81fa1 100644
--- a/AK/Vector.h
+++ b/AK/Vector.h
@@ -17,13 +17,7 @@
 #include <AK/Traits.h>
 #include <AK/TypedTransfer.h>
 #include <AK/kmalloc.h>
-
-// NOTE: We can't include <initializer_list> during the toolchain bootstrap,
-//       since it's part of libstdc++, and libstdc++ depends on LibC.
-//       For this reason, we don't support Vector(initializer_list) in LibC.
-#ifndef SERENITY_LIBC_BUILD
-#    include <initializer_list>
-#endif
+#include <initializer_list>
 
 #ifndef __serenity__
 #    include <new>
@@ -65,14 +59,12 @@ public:
     {
     }
 
-#ifndef SERENITY_LIBC_BUILD
     Vector(std::initializer_list<T> list) requires(!IsLvalueReference<T>)
     {
         ensure_capacity(list.size());
         for (auto& item : list)
             unchecked_append(item);
     }
-#endif
 
     Vector(Vector&& other)
         : m_size(other.m_size)
diff --git a/Userland/Libraries/LibC/CMakeLists.txt b/Userland/Libraries/LibC/CMakeLists.txt
index 98b31ba2271..aab4d8aa9b8 100644
--- a/Userland/Libraries/LibC/CMakeLists.txt
+++ b/Userland/Libraries/LibC/CMakeLists.txt
@@ -85,7 +85,7 @@ elseif ("${SERENITY_ARCH}" STREQUAL "x86_64")
     set(CRTN_SOURCE "arch/x86_64/crtn.S")
 endif()
 
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unknown-warning-option -DSERENITY_LIBC_BUILD")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unknown-warning-option")
 
 add_library(crt0 STATIC crt0.cpp)
 add_custom_command(