diff --git a/ml-proto/spec/eval.ml b/ml-proto/spec/eval.ml
index acc40f8660..3a0492a4a1 100644
--- a/ml-proto/spec/eval.ml
+++ b/ml-proto/spec/eval.ml
@@ -279,17 +279,15 @@ and eval_hostop c hostop vs at =
   | GrowMemory, [v] ->
     let mem = memory c at in
     let delta = address32 v at in
-    if I64.rem_u delta Memory.page_size <> 0L then
-      Trap.error at "growing memory by non-multiple of page size";
-    let old_size = (Memory.size mem) in
-    let new_size = Int64.add old_size delta in
+    let old_size = Memory.size mem in
+    let new_size = Int64.(add old_size (mul delta Memory.page_size)) in
     if I64.lt_u new_size old_size then
       Trap.error at "memory size overflow";
     (* Test whether the new size overflows the memory type.
      * Since we currently only support i32, just test that. *)
     if I64.gt_u new_size (Int64.of_int32 Int32.max_int) then
       Trap.error at "memory size exceeds implementation limit";
-    Memory.grow mem (Int64.div delta Memory.page_size);
+    Memory.grow mem delta;
     Some (Int32 (Int64.to_int32 old_size))
 
   | _, _ ->
diff --git a/ml-proto/test/memory_trap.wast b/ml-proto/test/memory_trap.wast
index 94535d4c28..18d8a53397 100644
--- a/ml-proto/test/memory_trap.wast
+++ b/ml-proto/test/memory_trap.wast
@@ -2,13 +2,14 @@
     (memory 1)
 
     (export "store" $store)
-    (func $store (param $i i32) (param $v i32) (result i32) (i32.store (i32.add (memory_size) (get_local $i)) (get_local $v)))
+    (func $store (param $i i32) (param $v i32) (result i32)
+      (i32.store (i32.add (memory_size) (get_local $i)) (get_local $v))
+    )
 
     (export "load" $load)
-    (func $load (param $i i32) (result i32) (i32.load (i32.add (memory_size) (get_local $i))))
-
-    (export "grow_memory" $grow_memory)
-    (func $grow_memory (param $i i32) (grow_memory (get_local $i)))
+    (func $load (param $i i32) (result i32)
+      (i32.load (i32.add (memory_size) (get_local $i)))
+    )
 
     (export "overflow_memory_size" $overflow_memory_size)
     (func $overflow_memory_size
@@ -28,5 +29,4 @@
 (assert_trap (invoke "load" (i32.const 0)) "out of bounds memory access")
 (assert_trap (invoke "store" (i32.const 0x80000000) (i32.const 13)) "out of bounds memory access")
 (assert_trap (invoke "load" (i32.const 0x80000000)) "out of bounds memory access")
-(assert_trap (invoke "grow_memory" (i32.const 3)) "growing memory by non-multiple of page size")
 (assert_trap (invoke "overflow_memory_size") "memory size exceeds implementation limit")
diff --git a/ml-proto/test/resizing.wast b/ml-proto/test/resizing.wast
index 132e0813e1..727f23847c 100644
--- a/ml-proto/test/resizing.wast
+++ b/ml-proto/test/resizing.wast
@@ -1,12 +1,6 @@
 (module
     (memory 0)
 
-    (export "round_up_to_page" $round_up_to_page)
-    (func $round_up_to_page (param i32) (result i32)
-      (i32.and (i32.add (get_local 0) (i32.const 0xFFFF))
-                              (i32.const 0xFFFF0000))
-    )
-
     (export "load_at_zero" $load_at_zero)
     (func $load_at_zero (result i32) (i32.load (i32.const 0)))
 
@@ -20,32 +14,26 @@
     (func $store_at_page_size (result i32) (i32.store (i32.const 0x10000) (i32.const 3)))
 
     (export "grow" $grow)
-    (func $grow (param $sz i32) (result i32)
-      (grow_memory (call $round_up_to_page (get_local $sz)))
-    )
-
-    (export "size_at_least" $size_at_least)
-    (func $size_at_least (param i32) (result i32) (i32.ge_u (memory_size) (get_local 0)))
+    (func $grow (param $sz i32) (result i32) (grow_memory (get_local $sz)))
 
     (export "size" $size)
     (func $size (result i32) (memory_size))
 )
 
 (assert_return (invoke "size") (i32.const 0))
-(assert_return (invoke "size_at_least" (i32.const 0)) (i32.const 1))
 (assert_trap (invoke "store_at_zero") "out of bounds memory access")
 (assert_trap (invoke "load_at_zero") "out of bounds memory access")
 (assert_trap (invoke "store_at_page_size") "out of bounds memory access")
 (assert_trap (invoke "load_at_page_size") "out of bounds memory access")
-(assert_return (invoke "grow" (i32.const 4)) (i32.const 0))
-(assert_return (invoke "size_at_least" (i32.const 4)) (i32.const 1))
+(assert_return (invoke "grow" (i32.const 1)) (i32.const 0))
+(assert_return (invoke "size") (i32.const 0x10000))
 (assert_return (invoke "load_at_zero") (i32.const 0))
 (assert_return (invoke "store_at_zero") (i32.const 2))
 (assert_return (invoke "load_at_zero") (i32.const 2))
 (assert_trap (invoke "store_at_page_size") "out of bounds memory access")
 (assert_trap (invoke "load_at_page_size") "out of bounds memory access")
-(assert_return (invoke "grow" (i32.const 4)) (i32.const 65536))
-(assert_return (invoke "size_at_least" (i32.const 8)) (i32.const 1))
+(assert_return (invoke "grow" (i32.const 4)) (i32.const 0x10000))
+(assert_return (invoke "size") (i32.const 0x50000))
 (assert_return (invoke "load_at_zero") (i32.const 2))
 (assert_return (invoke "store_at_zero") (i32.const 2))
 (assert_return (invoke "load_at_page_size") (i32.const 0))