diff --git a/common.mk b/common.mk
index ce3a01eb55..07e03bd2d5 100644
--- a/common.mk
+++ b/common.mk
@@ -1119,12 +1119,12 @@ OPTS =
 # This command compares trunk and built-ruby and 2.2.2
 benchmark: miniruby$(EXEEXT) PHONY
 	$(BASERUBY) $(srcdir)/benchmark/driver.rb -v \
-	            --executables="$(COMPARE_RUBY) -I$(srcdir)/lib -I. -I$(EXTOUT)/common --disable-gem; built-ruby::$(MINIRUBY) --disable-gem" \
+	            --executables="$(COMPARE_RUBY) -I$(srcdir)/lib -I. -I$(EXTOUT)/common --disable-gem; built-ruby::$(MINIRUBY) -r$(srcdir)/prelude --disable-gem" \
 	            --pattern='bm_' --directory=$(srcdir)/benchmark $(OPTS)
 
 benchmark-each: miniruby$(EXEEXT) PHONY
 	$(BASERUBY) $(srcdir)/benchmark/driver.rb -v \
-	            --executables="$(COMPARE_RUBY) -I$(srcdir)/lib -I. -I$(EXTOUT)/common --disable-gem; built-ruby::$(MINIRUBY) --disable-gem" \
+	            --executables="$(COMPARE_RUBY) -I$(srcdir)/lib -I. -I$(EXTOUT)/common --disable-gem; built-ruby::$(MINIRUBY) -r$(srcdir)/prelude --disable-gem" \
 	            --pattern=$(ITEM) --directory=$(srcdir)/benchmark $(OPTS)
 
 run.gdb: