diff --git a/hw/chimera_pkg.sv b/hw/chimera_pkg.sv
index c13b2f5..4622ba5 100644
--- a/hw/chimera_pkg.sv
+++ b/hw/chimera_pkg.sv
@@ -195,7 +195,7 @@ ExtClusters
     return chimera_cfg;
   endfunction : gen_chimera_cfg_isolate
 
-  localparam int NumCfgs = 2;
+  localparam int unsigned NumCfgs = 2;
 
   localparam chimera_cfg_t [NumCfgs-1:0] ChimeraCfg = {
     gen_chimera_cfg_isolate(),  // 1: Configuration with Isolation for Power Managemenet
diff --git a/target/sim/vsim/start.chimera_soc.tcl b/target/sim/vsim/start.chimera_soc.tcl
index aa50167..0e7158b 100644
--- a/target/sim/vsim/start.chimera_soc.tcl
+++ b/target/sim/vsim/start.chimera_soc.tcl
@@ -16,7 +16,7 @@ if {![info exists VOPTARGS]} {
 }
 
 set flags "-permissive -suppress 3009 -suppress 8386 -error 7 "
-if {[info exists SELCFG]} { append flags "-GSelectedCfg=${SELCFG} " }
+if {[info exists SELCFG]} { append flags "-gSelectedCfg=${SELCFG} " }
 
 set pargs ""
 if {[info exists BOOTMODE]} { append pargs "+BOOTMODE=${BOOTMODE} " }