diff --git a/passes/techmap/dfflibmap.cc b/passes/techmap/dfflibmap.cc
index e8fc6fc12..fa8939fd3 100644
--- a/passes/techmap/dfflibmap.cc
+++ b/passes/techmap/dfflibmap.cc
@@ -694,6 +694,8 @@ struct DfflibmapPass : public Pass {
 			for (auto it : cell_mappings)
 				dfflegalize_cmd += stringf(" -cell %s 01", it.first);
 			dfflegalize_cmd += " t:$_DFF* t:$_SDFF*";
+			for (auto module : design->selected_modules())
+				dfflegalize_cmd += " " + module -> name.str();
 			if (info_mode) {
 				log("dfflegalize command line: %s\n", dfflegalize_cmd);
 			} else {
diff --git a/tests/techmap/dfflibmap.ys b/tests/techmap/dfflibmap.ys
index 303daee48..087a0e5ff 100644
--- a/tests/techmap/dfflibmap.ys
+++ b/tests/techmap/dfflibmap.ys
@@ -97,3 +97,14 @@ select -assert-count 1 t:dffe
 # but we have to invert it because the CLEAR pin is active low.
 # ff2.CLEAR = !R
 select -assert-count 1 c:ff2 %x:+[CLEAR] %ci t:$_NOT_ %i
+
+# Test that dfflibmap respects selection and doesn't run dfflegalize on unselected modules
+design -load orig
+copy top top_unmapped
+dfflibmap -liberty dfflibmap.lib top
+# top should be mapped
+select -module top -assert-count 1 t:dffn
+# top_unmapped should have no mapped cells
+select -module top_unmapped -assert-none t:dffn
+select -module top_unmapped -assert-none t:dffe
+select -module top_unmapped -assert-none t:dffsr