@@ -820,7 +820,7 @@ impl AsSequence for PyByteArray {
             }),
             repeat: atomic_func!(|seq, n, vm| {
                 PyByteArray::sequence_downcast(seq)
-                    .mul(n as isize, vm)
+                    .mul(n, vm)
                     .map(|x| x.into_pyobject(vm))
             }),
             item: atomic_func!(|seq, i, vm| {
@@ -849,7 +849,7 @@ impl AsSequence for PyByteArray {
             }),
             inplace_repeat: atomic_func!(|seq, n, vm| {
                 let zelf = PyByteArray::sequence_downcast(seq).to_owned();
-                PyByteArray::imul(zelf, n as isize, vm).map(|x| x.into())
+                PyByteArray::imul(zelf, n, vm).map(|x| x.into())
             }),
         };
         &AS_SEQUENCE
 
@@ -432,7 +432,7 @@ impl AsSequence for PyList {
             }),
             repeat: atomic_func!(|seq, n, vm| {
                 PyList::sequence_downcast(seq)
-                    .mul(n as isize, vm)
+                    .mul(n, vm)
                     .map(|x| x.into())
             }),
             item: atomic_func!(|seq, i, vm| {
@@ -458,7 +458,7 @@ impl AsSequence for PyList {
             }),
             inplace_repeat: atomic_func!(|seq, n, vm| {
                 let zelf = PyList::sequence_downcast(seq);
-                zelf.borrow_vec_mut().imul(vm, n as isize)?;
+                zelf.borrow_vec_mut().imul(vm, n)?;
                 Ok(zelf.to_owned().into())
             }),
         };
 
@@ -353,7 +353,7 @@ impl AsSequence for PyTuple {
             }),
             repeat: atomic_func!(|seq, n, vm| {
                 let zelf = PyTuple::sequence_downcast(seq);
-                PyTuple::mul(zelf.to_owned(), n as isize, vm).map(|x| x.into())
+                PyTuple::mul(zelf.to_owned(), n, vm).map(|x| x.into())
             }),
             item: atomic_func!(|seq, i, vm| {
                 let zelf = PyTuple::sequence_downcast(seq);
 
@@ -525,7 +525,7 @@ mod _collections {
                 }),
                 repeat: atomic_func!(|seq, n, vm| {
                     PyDeque::sequence_downcast(seq)
-                        .mul(n as isize, vm)
+                        .mul(n, vm)
                         .map(|x| x.into_ref(vm).into())
                 }),
                 item: atomic_func!(|seq, i, vm| PyDeque::sequence_downcast(seq).getitem(i, vm)),
@@ -547,7 +547,7 @@ mod _collections {
                 }),
                 inplace_repeat: atomic_func!(|seq, n, vm| {
                     let zelf = PyDeque::sequence_downcast(seq);
-                    PyDeque::imul(zelf.to_owned(), n as isize, vm).map(|x| x.into())
+                    PyDeque::imul(zelf.to_owned(), n, vm).map(|x| x.into())
                 }),
             };
 
 
@@ -196,7 +196,7 @@ impl VirtualMachine {
         if let Some(slot_a) = slot_a {
             if let Some(slot_b) = slot_b {
                 // Check if `a` is subclass of `b`
-                if b.fast_isinstance(&a.class()) {
+                if b.fast_isinstance(a.class()) {
                     let ret = slot_b(num_a, b, self)?;
                     if ret.rich_compare_bool(
                         self.ctx.not_implemented.as_object(),