diff --git a/nac3core/src/codegen/irrt/numpy/ndarray.rs b/nac3core/src/codegen/irrt/numpy/ndarray.rs
index 2e510dce..7085cba4 100644
--- a/nac3core/src/codegen/irrt/numpy/ndarray.rs
+++ b/nac3core/src/codegen/irrt/numpy/ndarray.rs
@@ -204,7 +204,7 @@ fn call_nac3_ndarray_set_strides_by_shape<'ctx, G: CodeGenerator + ?Sized>(
 
     FunctionBuilder::begin(
         ctx,
-        &get_sized_dependent_function_name(sizet, "__nac3_ndarray_util_assert_shape_no_negative"),
+        &get_sized_dependent_function_name(sizet, "__nac3_ndarray_set_strides_by_shape"),
     )
     .arg("ndarray", &PointerModel(StructModel(NpArray { sizet })), ndarray_ptr)
     .returning_void();
@@ -217,12 +217,9 @@ fn call_nac3_ndarray_nbytes<'ctx, G: CodeGenerator + ?Sized>(
 ) -> Int<'ctx> {
     let sizet = IntModel(generator.get_size_type(ctx.ctx));
 
-    FunctionBuilder::begin(
-        ctx,
-        &get_sized_dependent_function_name(sizet, "__nac3_ndarray_util_assert_shape_no_negative"),
-    )
-    .arg("ndarray", &PointerModel(StructModel(NpArray { sizet })), ndarray_ptr)
-    .returning("nbytes", &sizet)
+    FunctionBuilder::begin(ctx, &get_sized_dependent_function_name(sizet, "__nac3_ndarray_nbytes"))
+        .arg("ndarray", &PointerModel(StructModel(NpArray { sizet })), ndarray_ptr)
+        .returning("nbytes", &sizet)
 }
 
 pub fn call_nac3_ndarray_fill_generic<'ctx, G: CodeGenerator + ?Sized>(
diff --git a/nac3core/src/codegen/model/pointer.rs b/nac3core/src/codegen/model/pointer.rs
index bbe0bb93..974f952d 100644
--- a/nac3core/src/codegen/model/pointer.rs
+++ b/nac3core/src/codegen/model/pointer.rs
@@ -77,4 +77,16 @@ impl<'ctx> OpaquePointer<'ctx> {
     pub fn store(&self, ctx: &CodeGenContext<'ctx, '_>, value: BasicValueEnum<'ctx>) {
         ctx.builder.build_store(self.0, value).unwrap();
     }
+
+    pub fn from_ptr(ctx: &CodeGenContext<'ctx, '_>, ptr: PointerValue<'ctx>) -> Self {
+        let ptr = ctx
+            .builder
+            .build_pointer_cast(
+                ptr,
+                ctx.ctx.i8_type().ptr_type(AddressSpace::default()),
+                "opaque.from_ptr",
+            )
+            .unwrap();
+        OpaquePointer(ptr)
+    }
 }
diff --git a/nac3core/src/codegen/numpy_new.rs b/nac3core/src/codegen/numpy_new.rs
index f726d5f8..21520b65 100644
--- a/nac3core/src/codegen/numpy_new.rs
+++ b/nac3core/src/codegen/numpy_new.rs
@@ -55,9 +55,16 @@ where
     let ndarray_ptr = call_ndarray_empty_impl(generator, ctx, elem_ty, shape, shape_ty, name)?;
 
     // NOTE: fill_value's type is not checked!! so be careful with logics
-    let fill_value_ptr =
-        OpaquePointer(ctx.builder.build_alloca(fill_value.get_type(), "fill_value_ptr").unwrap());
-    fill_value_ptr.store(ctx, fill_value);
+
+    // Allocate fill_value on the stack and give the corresponding stack pointer
+    // to call_nac3_ndarray_fill_generic
+    let fill_value_ptr = ctx.builder.build_alloca(fill_value.get_type(), "fill_value_ptr").unwrap();
+    ctx.builder.build_store(fill_value_ptr, fill_value).unwrap();
+
+    // Opaque-ize fill_value_ptr (turning it into `i8*`) before passing
+    // to call_nac3_ndarray_fill_generic
+    let fill_value_ptr = OpaquePointer::from_ptr(ctx, fill_value_ptr);
+
     call_nac3_ndarray_fill_generic(generator, ctx, &ndarray_ptr, &fill_value_ptr);
 
     Ok(ndarray_ptr)