diff --git a/sims.mk b/sims.mk
index f0c112203..fc9f544ef 100644
--- a/sims.mk
+++ b/sims.mk
@@ -25,6 +25,11 @@ test-sim-after-import: runsim
 	@echo "Running Iris simulation-after-import. This may take several minutes..."
 	@$(BINDIR)/runsim -Jobs=4 -SimAppPkg=$(SIMAPP) 25 5 TestIrisSimulationAfterImport
 
+test-sim-custom-genesis-multi-seed: runsim
+	@echo "Running multi-seed custom genesis simulation..."
+	@echo "By default, ${HOME}/.iris/config/genesis.json will be used."
+	@$(BINDIR)/runsim -Jobs=4 -Genesis=${HOME}/.iris/config/genesis.json 400 5 TestFullIrisSimulation
+
 test-sim-multi-seed-long: runsim
 	@echo "Running multi-seed application simulation. This may take awhile!"
 	@$(BINDIR)/runsim -Jobs=4 -SimAppPkg=$(SIMAPP) 500 50 TestFullAppSimulation