diff --git a/DESCRIPTION b/DESCRIPTION
index a30cb1ee..08b81411 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: tidypolars
 Type: Package
 Title: Get the Power of Polars with the Syntax of the Tidyverse
-Version: 0.3.0.9000
+Version: 0.4.0
 Authors@R: 
     person(given = "Etienne",
            family = "Bacher",
@@ -22,7 +22,7 @@ BugReports: https://github.com/etiennebacher/tidypolars/issues
 Depends: R (>= 4.1.0)
 Imports: 
     dplyr,
-    polars (>= 0.10.0),
+    polars (>= 0.11.0),
     rlang,
     tidyr,
     tidyselect
diff --git a/NEWS.md b/NEWS.md
index 1047e5c9..41bca107 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,4 +1,6 @@
-# tidypolars (development)
+# tidypolars 0.4.0
+
+`tidypolars` requires `polars` >= 0.11.0.
 
 **Breaking changes**
 
diff --git a/R/bind.R b/R/bind.R
index 7a285c6a..dcd0344b 100644
--- a/R/bind.R
+++ b/R/bind.R
@@ -27,7 +27,7 @@
 #' bind_rows_polars(p1, p2, .id = "id")
 
 bind_rows_polars <- function(..., .id = NULL) {
-  concat_(..., how = "diagonal", .id = .id)
+  concat_(..., how = "diagonal_relaxed", .id = .id)
 }
 
 #' Append multiple Data/LazyFrames next to each other
@@ -96,7 +96,7 @@ concat_ <- function(..., how, .id = NULL) {
   }
 
   if (how == "diagonal") {
-    pl$concat(dots, how = how, to_supertypes = TRUE)
+    pl$concat(dots, how = how)
   } else {
     pl$concat(dots, how = how)
   }
diff --git a/R/funs-default.R b/R/funs-default.R
index d57d9cae..483c48d6 100644
--- a/R/funs-default.R
+++ b/R/funs-default.R
@@ -194,22 +194,22 @@ pl_cosh <- function(x, ...) {
 
 pl_cumcount <- function(x, ...) {
   check_empty_dots(...)
-  x$cumcount()
+  x$cum_count()
 }
 
 pl_cummin <- function(x, ...) {
   check_empty_dots(...)
-  x$cummin()
+  x$cum_min()
 }
 
 pl_cumprod <- function(x, ...) {
   check_empty_dots(...)
-  x$cumprod()
+  x$cum_prod()
 }
 
 pl_cumsum <- function(x, ...) {
   check_empty_dots(...)
-  x$cumsum()
+  x$cum_sum()
 }
 
 pl_cumulative_eval <- function(x, ...) {
diff --git a/R/funs-string.R b/R/funs-string.R
index 1f5d009a..bd15bd47 100644
--- a/R/funs-string.R
+++ b/R/funs-string.R
@@ -4,7 +4,7 @@ pl_str_detect <- function(string, pattern, negate = FALSE, ...) {
   is_fixed <- isTRUE(attr(pattern, "stringr_attr") == "fixed")
   out <- string$str$contains(pattern, literal = is_fixed)
   if (isTRUE(negate)) {
-    out$is_not()
+    out$not()
   } else {
     out
   }
@@ -27,7 +27,7 @@ pl_str_ends <- function(string, pattern, negate = FALSE, ...) {
   check_empty_dots(...)
   out <- string$str$ends_with(pattern)
   if (isTRUE(negate)) {
-    out$is_not()
+    out$not()
   } else {
     out
   }
@@ -92,7 +92,7 @@ pl_str_slice <- function(string, start, end = NULL, ...) {
 pl_str_starts <- function(string, pattern, negate = FALSE, ...) {
   check_empty_dots(...)
   if (isTRUE(negate)) {
-    string$str$starts_with(pl$lit(pattern))$is_not()
+    string$str$starts_with(pl$lit(pattern))$not()
   } else {
     string$str$starts_with(pl$lit(pattern))
   }
@@ -194,7 +194,7 @@ pl_str_pad <- function(string, width, side = "left", pad = " ", use_width = TRUE
 
 pl_word <- function(string, start = 1L, end = start, sep = " ", ...) {
   check_empty_dots(...)
-  string$str$split(sep)$list$take((start:end) - 1L)$list$join(sep)
+  string$str$split(sep)$list$gather((start:end) - 1L)$list$join(sep)
 }
 
 pl_str_squish <- function(string, ...) {
diff --git a/R/polars.R b/R/polars.R
index 783d4937..f98f9729 100644
--- a/R/polars.R
+++ b/R/polars.R
@@ -3,3 +3,5 @@
 #' @import tidyr
 #' @export
 NULL
+
+data <- NULL
diff --git a/R/sink_csv.R b/R/sink_csv.R
index 097ccd1f..2916524a 100644
--- a/R/sink_csv.R
+++ b/R/sink_csv.R
@@ -5,7 +5,9 @@
 #' crashes because of too small memory.
 #'
 #' @param .data A Polars LazyFrame.
-#' @param has_header Whether to include header in the CSV output.
+#' @param include_bom Whether to include UTF-8 BOM (byte order mark) in the CSV
+#' output.
+#' @param include_header Whether to include header in the CSV output.
 #' @param separator Separate CSV fields with this symbol.
 #' @param line_terminator String used to end each row.
 #' @param quote Byte to use as quoting character.
@@ -61,7 +63,8 @@
 sink_csv <- function(
     .data,
     path,
-    has_header = TRUE,
+    include_bom = FALSE,
+    include_header = TRUE,
     separator = ",",
     line_terminator = "\n",
     quote = '"',
@@ -87,7 +90,8 @@ sink_csv <- function(
 
   .data$sink_csv(
     path = path,
-    has_header = has_header,
+    include_bom = include_bom,
+    include_header = include_header,
     separator = separator,
     line_terminator = line_terminator,
     quote = quote,
diff --git a/man/sink_csv.Rd b/man/sink_csv.Rd
index 7c547c39..2775f3c5 100644
--- a/man/sink_csv.Rd
+++ b/man/sink_csv.Rd
@@ -7,7 +7,8 @@
 sink_csv(
   .data,
   path,
-  has_header = TRUE,
+  include_bom = FALSE,
+  include_header = TRUE,
   separator = ",",
   line_terminator = "\\n",
   quote = "\\"",
@@ -32,7 +33,10 @@ sink_csv(
 
 \item{path}{Output file (must be a \code{.parquet} file).}
 
-\item{has_header}{Whether to include header in the CSV output.}
+\item{include_bom}{Whether to include UTF-8 BOM (byte order mark) in the CSV
+output.}
+
+\item{include_header}{Whether to include header in the CSV output.}
 
 \item{separator}{Separate CSV fields with this symbol.}