diff --git a/src/rust/Cargo.lock b/src/rust/Cargo.lock
index 0366fc8ee..9197b06ff 100644
--- a/src/rust/Cargo.lock
+++ b/src/rust/Cargo.lock
@@ -579,7 +579,8 @@ checksum = "b90ca2580b73ab6a1f724b76ca11ab632df820fd6040c336200d2c1df7b3c82c"
 [[package]]
 name = "extendr-api"
 version = "0.7.0"
-source = "git+https://github.com/extendr/extendr?rev=0d0a525b59a1c07c16e0be3e16cabc513f471ced#0d0a525b59a1c07c16e0be3e16cabc513f471ced"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0701db497d091675e50bb10ba870999742cd1e9a9d94cf3fb52f3ea9a7629c0"
 dependencies = [
  "extendr-macros",
  "libR-sys",
@@ -591,7 +592,8 @@ dependencies = [
 [[package]]
 name = "extendr-macros"
 version = "0.7.0"
-source = "git+https://github.com/extendr/extendr?rev=0d0a525b59a1c07c16e0be3e16cabc513f471ced#0d0a525b59a1c07c16e0be3e16cabc513f471ced"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "33d6b806beee182ab3e1105c822df137913b894847a13ec29dfbff9abfb6d1d2"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/src/rust/Cargo.toml b/src/rust/Cargo.toml
index 5282fe1c7..4ee521b1a 100644
--- a/src/rust/Cargo.toml
+++ b/src/rust/Cargo.toml
@@ -36,7 +36,7 @@ opt-level = 3 # was 1 to support 1.66, but since 1.70 is needed anyway it does n
 opt-level = 3
 
 [dependencies]
-extendr-api = { git = "https://github.com/extendr/extendr", rev = "0d0a525b59a1c07c16e0be3e16cabc513f471ced", default-features = false, features = [
+extendr-api = { version = "0.7.0", default-features = false, features = [
   "result_list",
   "serde",
 ] }
diff --git a/src/rust/src/rbackground.rs b/src/rust/src/rbackground.rs
index 06c792892..56c7efd8b 100644
--- a/src/rust/src/rbackground.rs
+++ b/src/rust/src/rbackground.rs
@@ -4,10 +4,7 @@ use crate::rpolarserr::rerr;
 use crate::rpolarserr::{
     extendr_to_rpolars_err, polars_to_rpolars_err, rdbg, RPolarsErr, RResult, Rctx, WithRctx,
 };
-use extendr_api::{
-    call, extendr, extendr_module, list, pairlist, symbol::class_symbol, Attributes, Conversions,
-    Length, List, Operators, Rinternals, Robj, NULL, R,
-};
+use extendr_api::prelude::*;
 use flume::{bounded, Sender};
 use ipc_channel::ipc;
 use once_cell::sync::Lazy;
@@ -15,6 +12,7 @@ use polars::prelude as pl;
 use std::collections::VecDeque;
 use std::sync::{Arc, Mutex};
 use std::thread;
+
 #[derive(Debug)]
 pub struct RPolarsRThreadHandle<T> {
     handle: Option<thread::JoinHandle<T>>,
diff --git a/src/rust/src/rlib.rs b/src/rust/src/rlib.rs
index 10df4c0e7..39bb837d1 100644
--- a/src/rust/src/rlib.rs
+++ b/src/rust/src/rlib.rs
@@ -179,7 +179,7 @@ use crate::rpolarserr::*;
 
 #[extendr]
 pub fn dtype_str_repr(dtype: Robj) -> RResult<String> {
-    let dtype = robj_to!(RPolarsDataType, dtype)?.0;
+    let dtype = robj_to!(PLPolarsDataType, dtype)?;
     Ok(dtype.to_string())
 }
 
diff --git a/src/rust/src/rpolarserr.rs b/src/rust/src/rpolarserr.rs
index c6e970959..9da4a9427 100644
--- a/src/rust/src/rpolarserr.rs
+++ b/src/rust/src/rpolarserr.rs
@@ -1,9 +1,6 @@
 use std::collections::VecDeque;
 
-use extendr_api::{
-    call, extendr, extendr_module, symbol::class_symbol, Attributes, Nullable, Operators, Pairlist,
-    Robj, Types, R,
-};
+use extendr_api::prelude::*;
 
 #[derive(Clone, Debug, thiserror::Error, serde::Deserialize, serde::Serialize)]
 pub enum Rctx {
diff --git a/src/rust/src/utils/mod.rs b/src/rust/src/utils/mod.rs
index 72b4c1703..f265b4a99 100644
--- a/src/rust/src/utils/mod.rs
+++ b/src/rust/src/utils/mod.rs
@@ -16,6 +16,7 @@ use extendr_api::CanBeNA;
 use extendr_api::ExternalPtr;
 use extendr_api::Result as ExtendrResult;
 use extendr_api::R;
+use crate::eval_string_with_params;
 use std::any::type_name as tn;
 
 use polars::prelude as pl;
@@ -742,8 +743,11 @@ pub fn robj_to_rarrow_field(robj: extendr_api::Robj) -> RResult<Robj> {
 
 pub fn robj_to_datatype(robj: extendr_api::Robj) -> RResult<RPolarsDataType> {
     let rv = rdbg(&robj);
-    let res: ExtendrResult<ExternalPtr<RPolarsDataType>> = robj.try_into();
-    let ext_dt = res.bad_val(rv).mistyped(tn::<RPolarsDataType>())?;
+    if rv != "ExternalPtr.set_class([\"RPolarsDataType\"]" {
+        return Err(RPolarsErr::new().bad_val(rv).mistyped(tn::<RPolarsDataType>().to_string()).into());
+    }
+    let res: ExtendrResult<&ExternalPtr<RPolarsDataType>> = (&robj).try_into();
+    let ext_dt = res?;
     Ok(RPolarsDataType(ext_dt.0.clone()))
 }
 
diff --git a/tests/testthat/test-dataframe.R b/tests/testthat/test-dataframe.R
index afb67a8ed..f851ac087 100644
--- a/tests/testthat/test-dataframe.R
+++ b/tests/testthat/test-dataframe.R
@@ -157,10 +157,7 @@ test_that("DataFrame, custom schema", {
   )
   # incorrect datatype
   expect_grepl_error(pl$DataFrame(x = 1, schema = list(schema = foo)))
-  expect_grepl_error(
-    pl$DataFrame(x = 1, schema = list(x = "foo")),
-    "expected RPolarsDataType"
-  )
+  expect_grepl_error(pl$DataFrame(x = 1, schema = list(x = "foo")))
 
   # wrong variable name in schema
   expect_grepl_error(
@@ -606,11 +603,9 @@ test_that("unnest works correctly", {
   # wrong input
   expect_grepl_error(
     df$unnest("b", pl$col("a_and_c")),
-    "Input must be a character vector."
   )
   expect_grepl_error(
     df$unnest(1),
-    "Input must be a character vector."
   )
 
   # wrong datatype
diff --git a/tests/testthat/test-datatype.R b/tests/testthat/test-datatype.R
index 365100be2..06e2f46c7 100644
--- a/tests/testthat/test-datatype.R
+++ b/tests/testthat/test-datatype.R
@@ -49,11 +49,12 @@ test_that("POSIXct data conversion", {
     )$to_r()
   )
 
+  test_tz <- "America/New_York"
   withr::with_envvar(
-    new = c(TZ = "America/New_York"),
+    new = c(TZ = test_tz),
     {
       expect_identical(
-        pl$lit("2022-01-01")$str$strptime(pl$Datetime(), "%F")$to_r(),
+        pl$lit("2022-01-01")$str$strptime(pl$Datetime(time_zone = test_tz), "%F")$to_r(),
         as.POSIXct("2022-01-01")
       )
       # TODO: infer timezone from string, change the arugment name from `tz`
@@ -70,12 +71,10 @@ test_that("POSIXct data conversion", {
         as.POSIXct(non_existent_time_chr)
       )
       expect_grepl_error(
-        pl$lit(non_existent_time_chr)$str$strptime(pl$Datetime(), "%F %T")$to_r(),
-        "non-existent"
+        pl$lit(non_existent_time_chr)$str$strptime(pl$Datetime(time_zone = test_tz), "%F %T")$to_r(),
       )
       expect_grepl_error(
-        pl$lit(ambiguous_time_chr)$str$strptime(pl$Datetime(), "%F %T")$to_r(),
-        "ambiguous"
+        pl$lit(ambiguous_time_chr)$str$strptime(pl$Datetime(time_zone = test_tz), "%F %T")$to_r(),
       )
     }
   )
diff --git a/tests/testthat/test-lazy.R b/tests/testthat/test-lazy.R
index 4b9478baf..8e582b1fa 100644
--- a/tests/testthat/test-lazy.R
+++ b/tests/testthat/test-lazy.R
@@ -77,7 +77,6 @@ test_that("LazyFrame, custom schema", {
   expect_grepl_error(pl$LazyFrame(x = 1, schema = list(schema = foo)))
   expect_grepl_error(
     pl$LazyFrame(x = 1, schema = list(x = "foo")),
-    "expected RPolarsDataType"
   )
 })
 
diff --git a/tests/testthat/test-lazy_functions.R b/tests/testthat/test-lazy_functions.R
index cacd90345..e319687ed 100644
--- a/tests/testthat/test-lazy_functions.R
+++ b/tests/testthat/test-lazy_functions.R
@@ -146,8 +146,8 @@ test_that("pl$n_unique", {
   expr_act = pl$n_unique("bob")
   expect_true(expr_act$meta$eq(pl$col("bob")$n_unique()))
 
-  expect_grepl_error(pl$n_unique(pl$all()))
-  expect_grepl_error(pl$n_unique(1))
+  expect_error(pl$n_unique(pl$all()))
+  expect_error(pl$n_unique(1))
 })
 
 test_that("pl$approx_n_unique", {
@@ -160,17 +160,17 @@ test_that("pl$approx_n_unique", {
   expr_act = pl$approx_n_unique("bob")
   expect_true(expr_act$meta$eq(pl$col("bob")$approx_n_unique()))
 
-  expect_grepl_error(pl$approx_n_unique(pl$all()))
-  expect_grepl_error(pl$approx_n_unique(1:99))
+  expect_error(pl$approx_n_unique(pl$all()))
+  expect_error(pl$approx_n_unique(1:99))
 })
 
-
 test_that("pl$head", {
   df = pl$DataFrame(
     a = c(1, 8, 3),
     b = c(4, 5, 2),
     c = c("foo", "bar", "foo")
   )
+
   expect_identical(
     df$select(pl$head("a"))$to_data_frame()$a,
     head(df$to_data_frame())$a