diff --git a/changelog_entry.yaml b/changelog_entry.yaml
index e69de29b..cacec347 100644
--- a/changelog_entry.yaml
+++ b/changelog_entry.yaml
@@ -0,0 +1,6 @@
+- bump: patch 
+  changes:
+    fixed:
+      - Removed the possibility of a negative seed in random() within commons/formulas.py
+    changed:
+      - As part of the negative seed fix in formulas.py, a single seed and generator was used to generate a random sequence, rather than a random number generator and seed combination being deployed for each entity id. This saves around 5-10 seconds of computation.
diff --git a/policyengine_core/commons/formulas.py b/policyengine_core/commons/formulas.py
index 4695cf9c..74178747 100644
--- a/policyengine_core/commons/formulas.py
+++ b/policyengine_core/commons/formulas.py
@@ -329,13 +329,8 @@ def random(population):
     entity_ids = population(f"{population.entity.key}_id", period)
 
     # Generate random values for each entity
-    values = np.array(
-        [
-            np.random.default_rng(
-                seed=id * 100 + population.simulation.count_random_calls
-            ).random()
-            for id in entity_ids
-        ]
+    values = np.random.default_rng(seed=min(entity_ids)).random(
+        size=len(entity_ids)
     )
 
     return values