1 files changed, 4 insertions, 0 deletions
diff --git a/src/VeriFuzz/Sim/Yosys.hs b/src/VeriFuzz/Sim/Yosys.hs
index b7fae6b..c432afe 100644
--- a/src/VeriFuzz/Sim/Yosys.hs
+++ b/src/VeriFuzz/Sim/Yosys.hs
@@ -20,6 +20,7 @@ module VeriFuzz.Sim.Yosys
     )
 where
 
+import           Control.DeepSeq          (NFData, rnf, rwhnf)
 import           Control.Lens
 import           Data.Text                (Text, unpack)
 import           Prelude                  hiding (FilePath)
@@ -49,6 +50,9 @@ instance Synthesiser Yosys where
   synthOutput = yosysOutput
   setSynthOutput (Yosys a b _) = Yosys a b
 
+instance NFData Yosys where
+    rnf = rwhnf
+
 defaultYosys :: Yosys
 defaultYosys = Yosys Nothing "yosys" "syn_yosys.v"