diff --git a/passes/techmap/abc9.cc b/passes/techmap/abc9.cc
index 6e424d517..ce057566c 100644
--- a/passes/techmap/abc9.cc
+++ b/passes/techmap/abc9.cc
@@ -1117,8 +1117,8 @@ struct Abc9Pass : public Pass {
 				auto derived_name = inst_module->derive(design, cell->parameters);
 				auto derived_module = design->module(derived_name);
 				log_assert(derived_module);
-				// FIXME: call once
-				Pass::call_on_module(design, derived_module, "proc");
+				if (derived_module->has_processes())
+					Pass::call_on_module(design, derived_module, "proc");
 				SigMap derived_sigmap(derived_module);
 
 				Wire *currQ = derived_module->wire("\\$currQ");