diff --git a/servers/vm/alloc.c b/servers/vm/alloc.c
index 5d9e6e497..5dbcbaa27 100644
--- a/servers/vm/alloc.c
+++ b/servers/vm/alloc.c
@@ -376,8 +376,14 @@ struct memlist *alloc_mem_in_list(phys_bytes bytes, u32_t flags, phys_bytes know
 
 	assert(!(flags & PAF_CONTIG));
 
-	if(known != MAP_NONE)
+	if(known != MAP_NONE) {
+		if(known == NO_MEM) {
+			printf("VM: odd mem for alloc_mem_in_list: 0x%lx\n",
+				known);
+			return NULL;
+		}
 		phys_count = known;
+	}
 
 	do {
 		struct memlist *ml;
@@ -426,19 +432,6 @@ struct memlist *alloc_mem_in_list(phys_bytes bytes, u32_t flags, phys_bytes know
 		rempages--;
 	} while(rempages > 0);
 
-    {
-	struct memlist *ml;
-	for(ml = head; ml; ml = ml->next) {
-		assert(ml->phys);
-#if NONCONTIGUOUS
-		if(!(flags & PAF_CONTIG)) {
-			if(ml->next)
-				assert(ml->phys + ml->length != ml->next->phys);
-		}
-#endif
-	}
-    }
-
 	return head;
 }
 
diff --git a/servers/vm/vm.h b/servers/vm/vm.h
index 66287dc37..edf205c41 100644
--- a/servers/vm/vm.h
+++ b/servers/vm/vm.h
@@ -1,6 +1,4 @@
 
-#define NO_MEM ((phys_clicks) 0)  /* returned by alloc_mem() with mem is up */
-
 /* Memory flags to pt_allocmap() and alloc_mem(). */
 #define PAF_CLEAR	0x01	/* Clear physical memory. */
 #define PAF_CONTIG	0x02	/* Physically contiguous. */
@@ -21,7 +19,6 @@
 /* VM behaviour */
 #define MEMPROTECT	0	/* Slab objects not mapped. Access with USE() */
 #define JUNKFREE	0	/* Fill freed pages with junk */
-#define NONCONTIGUOUS	0	/* Make phys pages max. noncontiguous */
 
 /* How noisy are we supposed to be? */
 #define VERBOSE		0
@@ -51,4 +48,5 @@
 #define WMF_VERIFY		0x08	/* Check pagetable contents. */
 
 #define MAP_NONE	0xFFFFFFFE
+#define NO_MEM ((phys_clicks) MAP_NONE)  /* returned by alloc_mem() with mem is up */