diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index e48deab8901d..bde47f3a8c9d 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -9,6 +9,7 @@
 
 #include <linux/types.h>
 #include <linux/ioctl.h>
+#include <linux/stddef.h>
 
 #define KVM_PIO_PAGE_OFFSET 1
 #define KVM_COALESCED_MMIO_PAGE_OFFSET 2
@@ -507,8 +508,8 @@ struct kvm_nested_state {
 	 * KVM_{GET,PUT}_NESTED_STATE ioctl values.
 	 */
 	union {
-		struct kvm_vmx_nested_state_data vmx[0];
-		struct kvm_svm_nested_state_data svm[0];
+		__DECLARE_FLEX_ARRAY(struct kvm_vmx_nested_state_data, vmx);
+		__DECLARE_FLEX_ARRAY(struct kvm_svm_nested_state_data, svm);
 	} data;
 };