diff --git a/common.mk b/common.mk
index 1fc5922710..96e452fc6c 100644
--- a/common.mk
+++ b/common.mk
@@ -1245,6 +1245,9 @@ run: fake miniruby$(EXEEXT) PHONY
 runruby: $(PROGRAM) PHONY
 	RUBY_ON_BUG='gdb -x $(srcdir)/.gdbinit -p' $(RUNRUBY) $(RUNOPT0) $(TESTRUN_SCRIPT) $(RUNOPT)
 
+runirb: $(PROGRAM) PHONY
+	RUBY_ON_BUG='gdb -x $(srcdir)/.gdbinit -p' $(RUNRUBY) $(RUNOPT0) -r irb -e 'IRB.start("make runirb")' $(RUNOPT)
+
 parse: fake miniruby$(EXEEXT) PHONY
 	$(BTESTRUBY) --dump=parsetree_with_comment,insns $(TESTRUN_SCRIPT)