diff --git a/Makefile.in b/Makefile.in
index 8087065bea..8d36063c97 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -89,7 +89,9 @@ PROGRAM=$(RUBY_INSTALL_NAME)$(EXEEXT)
 RUBY = $(RUBY_INSTALL_NAME)
 MINIRUBY = @MINIRUBY@\
 	$(MINIRUBYOPT)
-RUNRUBY = @RUNRUBY@ $(RUNRUBYOPT) -- $(RUN_OPTS)
+RUNRUBY_COMMAND = @RUNRUBY@ $(RUNRUBYOPT)
+RUNRUBY = $(RUNRUBY_COMMAND) -- $(RUN_OPTS)
+RUNRUBY_DEBUGGER = --debugger='gdb -x run.gdb --quiet --args'
 XRUBY = @XRUBY@
 BTESTRUBY = @BTESTRUBY@\
 	$(MINIRUBYOPT)
diff --git a/common.mk b/common.mk
index 910948e2d1..d2818f6808 100644
--- a/common.mk
+++ b/common.mk
@@ -954,7 +954,7 @@ gdb: miniruby$(EXEEXT) run.gdb PHONY
 	gdb -x run.gdb --quiet --args $(MINIRUBY) $(TESTRUN_SCRIPT)
 
 gdb-ruby: $(PROGRAM) run.gdb PHONY
-	gdb -x run.gdb --quiet --args $(PROGRAM) $(TESTRUN_SCRIPT)
+	$(Q) $(RUNRUBY_COMMAND) $(RUNRUBY_DEBUGGER) -- $(TESTRUN_SCRIPT)
 
 dist:
 	$(BASERUBY) $(srcdir)/tool/make-snapshot tmp $(RELNAME)