diff --git a/src/rt/arch/x86_64/morestack.S b/src/rt/arch/x86_64/morestack.S
index 7a17cb6744e..cabed0c9114 100644
--- a/src/rt/arch/x86_64/morestack.S
+++ b/src/rt/arch/x86_64/morestack.S
@@ -52,7 +52,7 @@
 	.type MORESTACK,@function
 #endif
 
-#if defined(__linux)
+#if defined(__linux__)
 MORESTACK:
 	.cfi_startproc