diff --git a/Cargo.lock b/Cargo.lock
index 86787124a..079b85695 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2213,9 +2213,8 @@ dependencies = [
 
 [[package]]
 name = "fsrs"
-version = "4.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1f3a8c3df2c324ebab71461178fe8c1fe2d7373cf603f312b652befd026f06d"
+version = "5.0.0"
+source = "git+https://github.com/open-spaced-repetition/fsrs-rs.git?branch=Refactor/expected_workload_via_dp#808bd715b302ccdda26a2d29c7566270e7be3bb3"
 dependencies = [
  "burn",
  "itertools 0.14.0",
diff --git a/Cargo.toml b/Cargo.toml
index 2ff29cd1a..212c79ea1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -33,8 +33,9 @@ git = "https://github.com/ankitects/linkcheck.git"
 rev = "184b2ca50ed39ca43da13f0b830a463861adb9ca"
 
 [workspace.dependencies.fsrs]
-version = "4.1.1"
-# git = "https://github.com/open-spaced-repetition/fsrs-rs.git"
+# version = "4.1.1"
+git = "https://github.com/open-spaced-repetition/fsrs-rs.git"
+branch = "Refactor/expected_workload_via_dp"
 # rev = "a7f7efc10f0a26b14ee348cc7402155685f2a24f"
 # path = "../open-spaced-repetition/fsrs-rs"
 
diff --git a/rslib/src/deckconfig/service.rs b/rslib/src/deckconfig/service.rs
index 21bcfd676..ba2bba3a1 100644
--- a/rslib/src/deckconfig/service.rs
+++ b/rslib/src/deckconfig/service.rs
@@ -103,43 +103,15 @@ impl crate::services::DeckConfigService for Collection {
         &mut self,
         input: anki_proto::deck_config::GetRetentionWorkloadRequest,
     ) -> Result<anki_proto::deck_config::GetRetentionWorkloadResponse> {
-        const LEARN_SPAN: usize = 365;
-        const TERMINATION_PROB: f32 = 1e-5;
-        // the default values are from https://github.com/open-spaced-repetition/Anki-button-usage/blob/881009015c2a85ac911021d76d0aacb124849937/analysis.ipynb
-        const DEFAULT_LEARN_COST: f32 = 19.4698;
-        const DEFAULT_PASS_COST: f32 = 7.8454;
-        const DEFAULT_FAIL_COST: f32 = 23.185;
-        const DEFAULT_INITIAL_PASS_RATE: f32 = 0.7645;
-
         let guard =
             self.search_cards_into_table(&input.search, crate::search::SortMode::NoOrder)?;
-        let costs = guard.col.storage.get_costs_for_retention()?;
+        
+        let revlogs = guard
+            .col
+            .storage
+            .get_revlog_entries_for_searched_cards_in_card_order()?;
 
-        fn smoothing(obs: f32, default: f32, count: u32) -> f32 {
-            let alpha = count as f32 / (50.0 + count as f32);
-            obs * alpha + default * (1.0 - alpha)
-        }
-
-        let cost_success = smoothing(
-            costs.average_pass_time_ms / 1000.0,
-            DEFAULT_PASS_COST,
-            costs.pass_count,
-        );
-        let cost_failure = smoothing(
-            costs.average_fail_time_ms / 1000.0,
-            DEFAULT_FAIL_COST,
-            costs.fail_count,
-        );
-        let cost_learn = smoothing(
-            costs.average_learn_time_ms / 1000.0,
-            DEFAULT_LEARN_COST,
-            costs.learn_count,
-        );
-        let initial_pass_rate = smoothing(
-            costs.initial_pass_rate,
-            DEFAULT_INITIAL_PASS_RATE,
-            costs.pass_count,
-        );
+        let config = guard.col.get_optimal_retention_parameters(revlogs)?;
 
         let costs = (70u32..=99u32)
             .map(|dr| {
@@ -148,12 +120,7 @@ impl crate::services::DeckConfigService for Collection {
                     fsrs::expected_workload(
                         &input.w,
                         dr as f32 / 100.,
-                        LEARN_SPAN,
-                        cost_success,
-                        cost_failure,
-                        cost_learn,
-                        initial_pass_rate,
-                        TERMINATION_PROB,
+                        &config
                     )?,
                 ))
             })