diff --git a/pkgs/quartus/quartus-unwrapped.nix b/pkgs/quartus/quartus-unwrapped.nix
index 6b7fade..7b52014 100644
--- a/pkgs/quartus/quartus-unwrapped.nix
+++ b/pkgs/quartus/quartus-unwrapped.nix
@@ -174,11 +174,11 @@ stdenvNoCC.mkDerivation (
       echo "Cleaning up logs..."
       rm -r $out/uninstall $out/logs
 
-      # replace /proc pentium check with a true statement. this allows usage under emulation.
-      ${lib.optionalString (quartusSource.variant != "pro") ''
-        substituteInPlace $out/quartus/adm/qenv.sh \
-          --replace-fail 'grep sse /proc/cpuinfo > /dev/null 2>&1' ':'
-      ''}
+      # replace /proc sse/sse4_2 check with a true statement. this allows usage under emulation.
+      substituteInPlace $out/quartus/adm/qenv.sh \
+        --replace-fail 'grep ${
+          if (quartusSource.variant == "pro") then "sse4_2" else "sse"
+        } /proc/cpuinfo > /dev/null 2>&1' ':'
     '';
 
     meta = {