diff --git a/changelog_entry.yaml b/changelog_entry.yaml
index e69de29bb2d..966790bff2e 100644
--- a/changelog_entry.yaml
+++ b/changelog_entry.yaml
@@ -0,0 +1,4 @@
+- bump: patch
+  changes:
+    fixed:
+      - Invalid value when dividing employment_income by total_earnings in marginal tax rate calculation.
diff --git a/policyengine_us/variables/household/marginal_tax_rate.py b/policyengine_us/variables/household/marginal_tax_rate.py
index fd435b48b51..0c066d88fc4 100644
--- a/policyengine_us/variables/household/marginal_tax_rate.py
+++ b/policyengine_us/variables/household/marginal_tax_rate.py
@@ -19,9 +19,14 @@ def formula(person, period, parameters):
         employment_income = person("employment_income", period)
         self_employment_income = person("self_employment_income", period)
         total_earnings = employment_income + self_employment_income
-        emp_self_emp_ratio = where(
-            total_earnings > 0, employment_income / total_earnings, 1
+
+        emp_self_emp_ratio = np.divide(
+            employment_income,
+            total_earnings,
+            out=np.ones_like(total_earnings, dtype=np.float32),
+            where=total_earnings > 0,
         )
+
         for adult_index in range(1, 1 + adult_count):
             alt_sim = sim.get_branch(f"mtr_for_adult_{adult_index}")
             for variable in sim.tax_benefit_system.variables: