diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 80a9325f5..c29905fd8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,6 +1,6 @@
 name: Testing
 
-on: [ push ]
+on: [ push, pull_request ]
 
 jobs:
   build:
diff --git a/README.md b/README.md
index 23559b6de..9fa42bf10 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # Hybrid Optimization and Performance Platform
 
+![CI Tests](https://github.com/NREL/HOPP/actions/workflows/ci.yml/badge.svg)
+
 As part of NREL's [Hybrid Energy Systems Research](https://www.nrel.gov/wind/hybrid-energy-systems-research.html), this
 software assesses optimal designs for the deployment of utility-scale hybrid energy plants, particularly considering wind,
 solar and storage.
diff --git a/hybrid/layout/pv_design_utils.py b/hybrid/layout/pv_design_utils.py
index c11a1dd35..0647e4688 100644
--- a/hybrid/layout/pv_design_utils.py
+++ b/hybrid/layout/pv_design_utils.py
@@ -108,7 +108,7 @@ def size_electrical_parameters(
         inverter_power=inverter_power,
         )
 
-    if n_inputs_combiner:
+    if n_inputs_combiner is not None and n_inputs_inverter is not None:
         n_combiners = math.ceil(n_strings / n_inputs_combiner)
         # Ensure there are enough inverters for the number of combiner boxes
         n_inverters = max(n_inverters, math.ceil(n_combiners / n_inputs_inverter))
diff --git a/tests/hybrid/test_hybrid.py b/tests/hybrid/test_hybrid.py
index bb9412a2c..015ccce46 100644
--- a/tests/hybrid/test_hybrid.py
+++ b/tests/hybrid/test_hybrid.py
@@ -266,7 +266,9 @@ def test_hybrid_detailed_pv_only(site):
             solar_only['pv']['tech_config']['cec_i_mp_ref'] \
             * solar_only['pv']['tech_config']['cec_v_mp_ref'] \
             * 1e-3,
-        inverter_power=solar_only['pv']['tech_config']['inv_snl_paco'] * 1e-3
+        inverter_power=solar_only['pv']['tech_config']['inv_snl_paco'] * 1e-3,
+        n_inputs_inverter=50,
+        n_inputs_combiner=32
     )
     assert n_strings == 13435
     assert n_combiners == 420