diff --git a/dev/sim/coco/Makefile.icarus.smt2 b/dev/sim/coco/Makefile.smt2
similarity index 100%
rename from dev/sim/coco/Makefile.icarus.smt2
rename to dev/sim/coco/Makefile.smt2
diff --git a/dev/sim/coco/Makefile.icarus b/dev/sim/coco/Makefile.st
similarity index 98%
rename from dev/sim/coco/Makefile.icarus
rename to dev/sim/coco/Makefile.st
index 3da686f..0ce3d4a 100755
--- a/dev/sim/coco/Makefile.icarus
+++ b/dev/sim/coco/Makefile.st
@@ -8,7 +8,7 @@
 
 #COCOTB_RESOLVE_X = ZEROS # VALUE_ERROR ZEROS ONES RANDOM
 
-#SIM_BUILD ?= build
+SIM_BUILD ?= build_st
 SIM ?= icarus
 
 # options
diff --git a/dev/sim/coco/build_st/cmds.f b/dev/sim/coco/build_st/cmds.f
new file mode 100644
index 0000000..3e26e00
--- /dev/null
+++ b/dev/sim/coco/build_st/cmds.f
@@ -0,0 +1 @@
++timescale+1ns/1ps
diff --git a/dev/sim/coco/results.xml b/dev/sim/coco/results.xml
old mode 100755
new mode 100644
index b6da424..a2ed940
--- a/dev/sim/coco/results.xml
+++ b/dev/sim/coco/results.xml
@@ -1,7 +1,7 @@
 <testsuites name="results">
   <testsuite name="all" package="all">
-    <property name="random_seed" value="1654605675" />
-    <testcase name="tb" classname="tb" file="/home/wtf/projects/a2o-opf/dev/sim/coco/tb.py" lineno="232" time="163.92313623428345" sim_time_ns="8177.000001" ratio_time="49.88313540629925">
+    <property name="random_seed" value="1657042106" />
+    <testcase name="tb" classname="tb" file="/home/wtf/projects/a2o/dev/sim/coco/tb.py" lineno="232" time="189.8742835521698" sim_time_ns="8225.000001" ratio_time="43.318135806106156">
       <failure />
     </testcase>
   </testsuite>