diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index c54817baabc7b41dd25cf80b154a25750bcbf1bd..63e89dfc808a6054addf05070f2a0ec70de89039 100644
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -115,7 +115,7 @@ static unsigned long get_mmap_base(int is_legacy)
 static void find_start_end(unsigned long flags, unsigned long *begin,
 			   unsigned long *end)
 {
-	if (!test_thread_flag(TIF_ADDR32) && (flags & MAP_32BIT)) {
+	if (!in_compat_syscall() && (flags & MAP_32BIT)) {
 		/* This is usually used needed to map code in small
 		   model, so it needs to be in the first 31bit. Limit
 		   it to that.  This means we need to move the
@@ -191,7 +191,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 		return addr;
 
 	/* for MAP_32BIT mappings we force the legacy mmap base */
-	if (!test_thread_flag(TIF_ADDR32) && (flags & MAP_32BIT))
+	if (!in_compat_syscall() && (flags & MAP_32BIT))
 		goto bottomup;
 
 	/* requesting a specific address */