diff --git a/tests/regression_tests/surface_source/inputs_true_read.dat b/tests/regression_tests/surface_source/inputs_true_read.dat
index b8827e8e1..aa181a299 100644
--- a/tests/regression_tests/surface_source/inputs_true_read.dat
+++ b/tests/regression_tests/surface_source/inputs_true_read.dat
@@ -20,6 +20,7 @@
   <surf_src_read>
     <path>surface_source_true.h5</path>
   </surf_src_read>
+  <seed>1</seed>
 </settings>
 <?xml version='1.0' encoding='utf-8'?>
 <tallies>
diff --git a/tests/regression_tests/surface_source/inputs_true_write.dat b/tests/regression_tests/surface_source/inputs_true_write.dat
index 6b28ae114..07dcf7dd2 100644
--- a/tests/regression_tests/surface_source/inputs_true_write.dat
+++ b/tests/regression_tests/surface_source/inputs_true_write.dat
@@ -26,6 +26,7 @@
     <surf_ids>1</surf_ids>
     <max_surf_banks>1000</max_surf_banks>
   </surf_src_write>
+  <seed>1</seed>
 </settings>
 <?xml version='1.0' encoding='utf-8'?>
 <tallies>
diff --git a/tests/regression_tests/surface_source/surface_source_true.h5 b/tests/regression_tests/surface_source/surface_source_true.h5
index c5cd61100..8aefd8159 100644
Binary files a/tests/regression_tests/surface_source/surface_source_true.h5 and b/tests/regression_tests/surface_source/surface_source_true.h5 differ
diff --git a/tests/regression_tests/surface_source/test.py b/tests/regression_tests/surface_source/test.py
index 7b0a8eb26..1dbd4abd2 100644
--- a/tests/regression_tests/surface_source/test.py
+++ b/tests/regression_tests/surface_source/test.py
@@ -39,6 +39,7 @@ def model(request):
     openmc_model.settings.run_mode = 'fixed source'
     openmc_model.settings.particles = 1000
     openmc_model.settings.batches = 10
+    openmc_model.settings.seed = 1
 
     if surf_src_op == 'write':
         point = openmc.stats.Point((0, 0, 0))