diff --git a/src/rt/arch/x86_64/_context.S b/src/rt/arch/x86_64/_context.S
index f718cac96347..a8af27e3e4fb 100644
--- a/src/rt/arch/x86_64/_context.S
+++ b/src/rt/arch/x86_64/_context.S
@@ -54,7 +54,7 @@ First four arguments:
         anyhow.
 */
 
-#if defined(__APPLE__) || defined(_WIN32)
+#if defined(__APPLE__)
 #define SWAP_REGISTERS _swap_registers
 #else
 #define SWAP_REGISTERS swap_registers
diff --git a/src/rt/arch/x86_64/ccall.S b/src/rt/arch/x86_64/ccall.S
index d4bc37fee957..dbee5bcdc90a 100644
--- a/src/rt/arch/x86_64/ccall.S
+++ b/src/rt/arch/x86_64/ccall.S
@@ -18,10 +18,13 @@
 
         .text
 
-#if defined(__APPLE__) || defined(_WIN32)
+#if defined(__APPLE__)
 .globl ___morestack
 .private_extern MORESTACK
 ___morestack:
+#elif defined(_WIN32)
+.globl __morestack
+__morestack:
 #else
 .globl __morestack
 .hidden __morestack
diff --git a/src/rt/arch/x86_64/morestack.S b/src/rt/arch/x86_64/morestack.S
index 9d16afc0a1b3..b718c9121c57 100644
--- a/src/rt/arch/x86_64/morestack.S
+++ b/src/rt/arch/x86_64/morestack.S
@@ -11,7 +11,7 @@
 
 .text
 
-#if defined(__APPLE__) || defined(_WIN32)
+#if defined(__APPLE__)
 #define UPCALL_NEW_STACK        _upcall_new_stack
 #define UPCALL_DEL_STACK        _upcall_del_stack
 #define MORESTACK               ___morestack