diff --git a/lib/libvmmapi/vmmapi.h b/lib/libvmmapi/vmmapi.h
--- a/lib/libvmmapi/vmmapi.h
+++ b/lib/libvmmapi/vmmapi.h
@@ -125,9 +125,9 @@
 int	vcpu_id(struct vcpu *vcpu);
 int	vm_parse_memsize(const char *optarg, size_t *memsize);
 int	vm_setup_memory(struct vmctx *ctx, size_t len, enum vm_mmap_style s);
-void	*vm_map_gpa(struct vmctx *ctx, vm_paddr_t gaddr, size_t len);
+void	*vm_map_gpa(struct vmctx *ctx, vm_paddr_t gaddr, size_t len) __result_use_check;
 /* inverse operation to vm_map_gpa - extract guest address from host pointer */
-vm_paddr_t vm_rev_map_gpa(struct vmctx *ctx, void *addr);
+vm_paddr_t vm_rev_map_gpa(struct vmctx *ctx, void *addr) __result_use_check;
 #ifdef __amd64__
 int	vm_get_gpa_pmap(struct vmctx *, uint64_t gpa, uint64_t *pte, int *num);
 int	vm_gla2gpa(struct vcpu *vcpu, struct vm_guest_paging *paging,
diff --git a/usr.sbin/bhyve/bhyverun.h b/usr.sbin/bhyve/bhyverun.h
--- a/usr.sbin/bhyve/bhyverun.h
+++ b/usr.sbin/bhyve/bhyverun.h
@@ -45,9 +45,9 @@
 struct vmctx;
 struct vm_run;
 
-void *paddr_guest2host(struct vmctx *ctx, uintptr_t addr, size_t len);
+void __result_use_check *paddr_guest2host(struct vmctx *ctx, uintptr_t addr, size_t len);
 #ifdef BHYVE_SNAPSHOT
-uintptr_t paddr_host2guest(struct vmctx *ctx, void *addr);
+uintptr_t __result_use_check paddr_host2guest(struct vmctx *ctx, void *addr);
 #endif
 
 struct vcpu;