diff --git a/src/core/CCVector.ml b/src/core/CCVector.ml
index 672433d30..42ae69484 100644
--- a/src/core/CCVector.ml
+++ b/src/core/CCVector.ml
@@ -202,43 +202,52 @@ let push v x =
 *)
 
 let resize_with v f size =
-  if size > Sys.max_array_length then
-    invalid_arg "vec.resize_with: size too big"
-  else if size > Array.length v.vec then
-    let new_vec = Array.make size (f 0) in
-    Array.blit v.vec 0 new_vec 0 (v.size - 1);
-    for i = v.size to size - 1 do
-       Array.unsafe_set new_vec i (f i)
-     done;
-    v.vec <- new_vec;
-    v.size <- size
+  let new_vec =
+    if size >= Array.length v.vec then
+      let new_vec = Array.make size (f 0) in
+      Array.blit v.vec 0 new_vec 0 (v.size - 1);
+      new_vec
+    else
+      v.vec
+  in
+  for i = v.size to size - 1 do
+    Array.unsafe_set new_vec i (f i)
+  done;
+  v.vec <- new_vec;
+  v.size <- size
 
 (*$T
-  let v = make 1 0 in to_list (resize_with v (fun i -> i) 5) = [0;1;2;3;4]
-  let v = make 1 0 in length (resize_with v (fun i -> i) 5) = 5
-
-  let v = make 5 0 in to_list (resize_with v (fun i -> i) 5) = [0;0;0;0;0]
-  let v = make 5 0 in to_list (resize_with v (fun i -> i) 6) = [0;0;0;0;0;6]
-  let v = make 5 0 in to_list (resize_with v (fun i -> i) -1) = [0;0;0;0;0]
-  let v = make 5 0 in length (resize_with v (fun i -> i) 5) = 5
+  let v = make 1 0 in resize_with v (fun i -> i) 5; to_list v = [0;1;2;3;4]
+  let v = make 1 0 in resize_with v (fun i -> i) 5; CCList.length (to_list v) = 5
+  let v = create_with ~capacity:2 0 in resize_with v (fun i -> i) 5; to_list v = [0;1;2;3;4]
+  let v = make 5 0 in resize_with v (fun i -> i) 5; to_list v = [0;0;0;0;0]
+  let v = make 5 0 in resize_with v (fun i -> i) 6; to_list v = [0;0;0;0;0;6]
+  let v = make 5 0 in resize_with v (fun i -> i) 4; to_list v = [0;0;0;0;0]
+  let v = make 5 0 in resize_with v (fun i -> i) 5; CCList.length (to_list v) = 5
 *)
 
 let resize_with_init v ~init size =
-  if size > Sys.max_array_length then
-    invalid_arg "vec.resize_with_init: size too big"
-  else if size > Array.length v.vec then
-    let new_vec = Array.make size init in
-    Array.blit v.vec 0 new_vec 0 (v.size - 1);
-    v.vec <- new_vec;
-    v.size <- size
+  let new_vec =
+    if size >= Array.length v.vec then
+      let new_vec = Array.make size init in
+      Array.blit v.vec 0 new_vec 0 (v.size - 1);
+      new_vec
+    else
+      v.vec
+  in
+  for i = v.size to size - 1 do
+    Array.unsafe_set new_vec i init
+  done;
+  v.vec <- new_vec;
+  v.size <- size
 
 (*$T
-  let v = make 1 0 in to_list (resize_with_init v ~init:1 5) = [1;1;1;1;1]
-  let v = make 1 0 in length (resize_with_init v ~init:1 5) = 5
-
-  let v = make 5 0 in to_list (resize_with_init v ~init:1 5) = [1;1;1;1;1]
-  let v = make 5 0 in to_list (resize_with_init v ~init:1 -1) = [1;1;1;1;1]
-  let v = make 5 0 in length (resize_with_init v ~init:1 5) = 5
+  let v = make 1 0 in resize_with_init v ~init:1 5; to_list v = [1;1;1;1;1]
+  let v = make 1 0 in resize_with_init v ~init:1 5; CCList.length (to_list v) = 5
+  let v = create_with ~capacity:2 0 in resize_with v ~init:1 5; to_list v = [1;1;1;1;1]
+  let v = make 5 0 in resize_with_init v ~init:1 5; to_list v = [1;1;1;1;1]
+  let v = make 5 0 in resize_with_init v ~init:1 4; to_list v = [1;1;1;1;1]
+  let v = make 5 0 in resize_with_init v ~init:1 5; CCList.length (to_list v) = 5
 *)
 
 (** Add all elements of b to a *)