diff --git a/libc/src/string/memory_utils/elements.h b/libc/src/string/memory_utils/elements.h
--- a/libc/src/string/memory_utils/elements.h
+++ b/libc/src/string/memory_utils/elements.h
@@ -657,7 +657,10 @@
 } // namespace scalar
 } // namespace __llvm_libc
 
+#if defined(LLVM_LIBC_ARCH_AARCH64)
 #include <src/string/memory_utils/elements_aarch64.h>
+#elif defined(LLVM_LIBC_ARCH_X86)
 #include <src/string/memory_utils/elements_x86.h>
+#endif
 
 #endif // LLVM_LIBC_SRC_STRING_MEMORY_UTILS_ELEMENTS_H
diff --git a/libc/src/string/memory_utils/elements_aarch64.h b/libc/src/string/memory_utils/elements_aarch64.h
--- a/libc/src/string/memory_utils/elements_aarch64.h
+++ b/libc/src/string/memory_utils/elements_aarch64.h
@@ -11,7 +11,9 @@
 
 #include "src/__support/architectures.h"
 
-#if defined(LLVM_LIBC_ARCH_AARCH64)
+#if !defined(LLVM_LIBC_ARCH_AARCH64)
+#error "Invalid include"
+#endif
 
 #include <src/string/memory_utils/elements.h>
 #include <stddef.h> // size_t
@@ -119,6 +121,4 @@
 } // namespace aarch64
 } // namespace __llvm_libc
 
-#endif // defined(LLVM_LIBC_ARCH_AARCH64)
-
 #endif // LLVM_LIBC_SRC_STRING_MEMORY_UTILS_ELEMENTS_AARCH64_H
diff --git a/libc/src/string/memory_utils/elements_x86.h b/libc/src/string/memory_utils/elements_x86.h
--- a/libc/src/string/memory_utils/elements_x86.h
+++ b/libc/src/string/memory_utils/elements_x86.h
@@ -9,9 +9,11 @@
 #ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_ELEMENTS_X86_H
 #define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_ELEMENTS_X86_H
 
-#include "src/__support/architectures.h"
+#if !defined(LLVM_LIBC_ARCH_X86)
+#error "Invalid include"
+#endif
 
-#if defined(LLVM_LIBC_ARCH_X86)
+#include "src/__support/architectures.h"
 
 #include <stddef.h> // size_t
 #include <stdint.h> // uint8_t, uint16_t, uint32_t, uint64_t
@@ -177,6 +179,4 @@
 } // namespace x86
 } // namespace __llvm_libc
 
-#endif // defined(LLVM_LIBC_ARCH_X86)
-
 #endif // LLVM_LIBC_SRC_STRING_MEMORY_UTILS_ELEMENTS_X86_H