Index: src/runtime/lookup-asm/lookup-asm-x86-win32.S
==================================================================
--- src/runtime/lookup-asm/lookup-asm-x86-win32.S
+++ src/runtime/lookup-asm/lookup-asm-x86-win32.S
@@ -53,15 +53,15 @@
 	jz	\not_found
 
 	ret
 
 .Ltagged_pointer_\name:
+	xor	edx, _objc_tagged_pointer_secret
 	and	dl, 0xE
 	movzx	edx, dl
 
-	mov	eax, offset _objc_tagged_pointer_classes
-	mov	edx, [eax+edx*2]
+	mov	edx, [_objc_tagged_pointer_classes+edx*2]
 	mov	edx, [edx+32]
 
 	jmp	short .Lmain_\name
 .endm
 

Index: src/runtime/lookup-asm/lookup-asm-x86_64-win64.S
==================================================================
--- src/runtime/lookup-asm/lookup-asm-x86_64-win64.S
+++ src/runtime/lookup-asm/lookup-asm-x86_64-win64.S
@@ -60,15 +60,15 @@
 	mov	rcx, r10
 	mov	rdx, r11
 	jmp	\not_found
 
 .Ltagged_pointer_\name:
+	xor	rcx, objc_tagged_pointer_secret
 	and	cl, 0xE
 	movzx	r8, cl
 
-	mov	rax, offset objc_tagged_pointer_classes
-	mov	r8, [rax+r8*4]
+	mov	r8, [objc_tagged_pointer_classes+r8*4]
 	mov	r8, [r8+56]
 
 	jmp	short .Lmain_\name
 .endm