diff --git a/NEWS.md b/NEWS.md
index 9eed3d701..8a9ac5eee 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -50,6 +50,7 @@
 - New method `$dt$time()` to extract the time from a `datetime` variable (#428).
 - New method `pl$read_parquet()` that is a shortcut for `pl$scan_parquet()$collect()` (#434).
 - Rename `$str$str_explode()` to `$str$explode()` (#436).
+- New argument `eager` of `LazyFrame$set_optimization_toggle()` (#439).
 
 # polars 0.8.1
 
diff --git a/R/extendr-wrappers.R b/R/extendr-wrappers.R
index a107ca392..6276af617 100644
--- a/R/extendr-wrappers.R
+++ b/R/extendr-wrappers.R
@@ -1055,7 +1055,7 @@ LazyFrame$schema <- function() .Call(wrap__LazyFrame__schema, self)
 
 LazyFrame$fetch <- function(n_rows) .Call(wrap__LazyFrame__fetch, self, n_rows)
 
-LazyFrame$set_optimization_toggle <- function(type_coercion, predicate_pushdown, projection_pushdown, simplify_expression, slice_pushdown, comm_subplan_elim, comm_subexpr_elim, streaming) .Call(wrap__LazyFrame__set_optimization_toggle, self, type_coercion, predicate_pushdown, projection_pushdown, simplify_expression, slice_pushdown, comm_subplan_elim, comm_subexpr_elim, streaming)
+LazyFrame$set_optimization_toggle <- function(type_coercion, predicate_pushdown, projection_pushdown, simplify_expression, slice_pushdown, comm_subplan_elim, comm_subexpr_elim, streaming, eager) .Call(wrap__LazyFrame__set_optimization_toggle, self, type_coercion, predicate_pushdown, projection_pushdown, simplify_expression, slice_pushdown, comm_subplan_elim, comm_subexpr_elim, streaming, eager)
 
 LazyFrame$get_optimization_toggle <- function() .Call(wrap__LazyFrame__get_optimization_toggle, self)
 
diff --git a/R/lazyframe__lazy.R b/R/lazyframe__lazy.R
index 097fc4f3b..5a3d856f7 100644
--- a/R/lazyframe__lazy.R
+++ b/R/lazyframe__lazy.R
@@ -306,6 +306,7 @@ LazyFrame_get_optimization_toggle = function() {
 #' reused.
 #' @param streaming Boolean. Run parts of the query in a streaming fashion
 #' (this is in an alpha state).
+#' @param eager Boolean. Run the query eagerly.
 #' @return LazyFrame with specified optimization toggles
 #' @examples
 #' pl$LazyFrame(mtcars)$set_optimization_toggle(type_coercion = FALSE)
@@ -317,7 +318,8 @@ LazyFrame_set_optimization_toggle = function(
     slice_pushdown = TRUE,
     comm_subplan_elim = TRUE,
     comm_subexpr_elim = TRUE,
-    streaming = FALSE) {
+    streaming = FALSE,
+    eager = FALSE) {
   self |>
     .pr$LazyFrame$set_optimization_toggle(
       type_coercion,
@@ -327,7 +329,8 @@ LazyFrame_set_optimization_toggle = function(
       slice_pushdown,
       comm_subplan_elim,
       comm_subexpr_elim,
-      streaming
+      streaming,
+      eager
     )
 }
 
diff --git a/man/LazyFrame_set_optimization_toggle.Rd b/man/LazyFrame_set_optimization_toggle.Rd
index d1d3db90e..f83f5eba7 100644
--- a/man/LazyFrame_set_optimization_toggle.Rd
+++ b/man/LazyFrame_set_optimization_toggle.Rd
@@ -12,7 +12,8 @@ LazyFrame_set_optimization_toggle(
   slice_pushdown = TRUE,
   comm_subplan_elim = TRUE,
   comm_subexpr_elim = TRUE,
-  streaming = FALSE
+  streaming = FALSE,
+  eager = FALSE
 )
 }
 \arguments{
@@ -39,6 +40,8 @@ reused.}
 
 \item{streaming}{Boolean. Run parts of the query in a streaming fashion
 (this is in an alpha state).}
+
+\item{eager}{Boolean. Run the query eagerly.}
 }
 \value{
 LazyFrame with specified optimization toggles
diff --git a/src/rust/src/lazy/dataframe.rs b/src/rust/src/lazy/dataframe.rs
index f219d4a87..eba494d53 100644
--- a/src/rust/src/lazy/dataframe.rs
+++ b/src/rust/src/lazy/dataframe.rs
@@ -510,6 +510,8 @@ impl LazyFrame {
         comm_subplan_elim: Robj,
         comm_subexpr_elim: Robj,
         streaming: Robj,
+        // fast_projection: Robj, // There is no method like with_fast_projection
+        eager: Robj,
     ) -> RResult<Self> {
         let ldf = self
             .0
@@ -519,6 +521,7 @@ impl LazyFrame {
             .with_simplify_expr(robj_to!(bool, simplify_expression)?)
             .with_slice_pushdown(robj_to!(bool, slice_pushdown)?)
             .with_streaming(robj_to!(bool, streaming)?)
+            ._with_eager(robj_to!(bool, eager)?)
             .with_projection_pushdown(robj_to!(bool, projection_pushdown)?)
             .with_comm_subplan_elim(robj_to!(bool, comm_subplan_elim)?)
             .with_comm_subexpr_elim(robj_to!(bool, comm_subexpr_elim)?);
@@ -549,6 +552,7 @@ impl LazyFrame {
             comm_subplan_elim = comm_subplan_elim,
             comm_subexpr_elim = comm_subexpr_elim,
             streaming = streaming,
+            eager = eager,
         )
     }
 
diff --git a/tests/testthat/test-lazy.R b/tests/testthat/test-lazy.R
index b976162cf..c13a1cbbc 100644
--- a/tests/testthat/test-lazy.R
+++ b/tests/testthat/test-lazy.R
@@ -805,7 +805,8 @@ test_that("opt_toggles", {
     slice_pushdown = FALSE,
     comm_subplan_elim = FALSE,
     comm_subexpr_elim = FALSE,
-    streaming = TRUE
+    streaming = TRUE,
+    eager = TRUE
   )
   opt_settings2 = lapply(opt_settings, `!`)