diff --git a/techlibs/common/synth.cc b/techlibs/common/synth.cc
index ccfa76e02..e41c0fe97 100644
--- a/techlibs/common/synth.cc
+++ b/techlibs/common/synth.cc
@@ -201,6 +201,8 @@ struct SynthPass : public ScriptPass
 			run("check");
 			run("opt");
 			run("wreduce");
+			run("peepopt");
+			run("opt_clean");
 			if (help_mode)
 				run("techmap -map +/cmp2lut.v", " (if -lut)");
 			else
diff --git a/techlibs/ice40/synth_ice40.cc b/techlibs/ice40/synth_ice40.cc
index 8899bfcc4..f5249e567 100644
--- a/techlibs/ice40/synth_ice40.cc
+++ b/techlibs/ice40/synth_ice40.cc
@@ -239,6 +239,8 @@ struct SynthIce40Pass : public ScriptPass
 			run("check");
 			run("opt");
 			run("wreduce");
+			run("peepopt");
+			run("opt_clean");
 			run("share");
 			run("techmap -map +/cmp2lut.v -D LUT_WIDTH=4");
 			run("opt_expr");