diff --git a/sys/vm/vm_extern.h b/sys/vm/vm_extern.h
--- a/sys/vm/vm_extern.h
+++ b/sys/vm/vm_extern.h
@@ -140,6 +140,11 @@
 static inline bool
 vm_addr_align_ok(vm_paddr_t pa, u_long alignment)
 {
+#ifdef INVARIANTS
+	if (!powerof2(alignment))
+		panic("%s: alignment is not a power of 2: %#lx",
+		    __func__, alignment);
+#endif
 	return ((pa & (alignment - 1)) == 0);
 }
 
@@ -150,6 +155,11 @@
 static inline bool
 vm_addr_bound_ok(vm_paddr_t pa, vm_paddr_t size, vm_paddr_t boundary)
 {
+#ifdef INVARIANTS
+	if (!powerof2(boundary))
+		panic("%s: boundary is not a power of 2: %#jx",
+		    __func__, (uintmax_t)boundary);
+#endif
 	return (((pa ^ (pa + size - 1)) & -boundary) == 0);
 }