diff --git a/changelog_entry.yaml b/changelog_entry.yaml
index e69de29b..1fa7f744 100644
--- a/changelog_entry.yaml
+++ b/changelog_entry.yaml
@@ -0,0 +1,4 @@
+- bump: minor
+  changes:
+    fixed:
+    - Bug causing subsample to not work in some situations.
diff --git a/policyengine_core/simulations/simulation.py b/policyengine_core/simulations/simulation.py
index 482c90e4..a18312c2 100644
--- a/policyengine_core/simulations/simulation.py
+++ b/policyengine_core/simulations/simulation.py
@@ -1549,6 +1549,14 @@ def subsample(
         # Update the dataset and rebuild the simulation
         self.dataset = Dataset.from_dataframe(df, self.dataset.time_period)
         self.build_from_dataset()
+
+        # Ensure the baseline branch has the new data.
+        if "baseline" in self.branches:
+            baseline_tax_benefit_system = self.branches[
+                "baseline"
+            ].tax_benefit_system
+            self.branches["baseline"] = self.clone()
+            self.branches["tax_benefit_system"] = baseline_tax_benefit_system
         return self