diff --git a/Makefile b/Makefile
index f86f272ea..32b0896eb 100644
--- a/Makefile
+++ b/Makefile
@@ -739,6 +739,7 @@ include $(YOSYS_SRC)/frontends/ast/Makefile.inc
 include $(YOSYS_SRC)/frontends/blif/Makefile.inc
 
 include $(YOSYS_SRC)/frontends/liberty/Makefile.inc
+include $(YOSYS_SRC)/frontends/json/Makefile.inc
 include $(YOSYS_SRC)/passes/equiv/Makefile.inc
 
 include $(YOSYS_SRC)/passes/cmds/Makefile.inc