diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0d560c702cc..596a569b486 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -44,6 +44,7 @@ config X86_LONGMODE
 	bool
 	prompt "Run in long (64-bit) mode"
 	default n
+	select 64BIT
 
 config MAX_IRQ_LINES
 	int "Number of IRQ lines"