diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c
index e11f9b18ac..b5093497d9 100644
--- a/src/pkg/runtime/proc.c
+++ b/src/pkg/runtime/proc.c
@@ -1696,6 +1696,7 @@ exitsyscall0(G *gp)
 }
 
 // Called from syscall package before fork.
+#pragma textflag NOSPLIT
 void
 syscall·runtime_BeforeFork(void)
 {