diff --git a/repos/base-hw/src/core/spec/x86_64/mode_transition.s b/repos/base-hw/src/core/spec/x86_64/mode_transition.s
index 52f1d1bc2e..3303224210 100644
--- a/repos/base-hw/src/core/spec/x86_64/mode_transition.s
+++ b/repos/base-hw/src/core/spec/x86_64/mode_transition.s
@@ -246,6 +246,14 @@
 
 	iretq
 
+	/* VM entry: Switch to guest VM */
+
+	.global _vt_vm_entry
+	_vt_vm_entry:
+	sti
+	mov $1, %rax
+	vmcall
+
 	/************************************************
 	 ** Space for Interrupt Descriptor Table (IDT) **
 	 ** See Intel SDM Vol. 3A, section 6.10        **