diff --git a/common.mk b/common.mk
index 07f07799fb..05cb3946cf 100644
--- a/common.mk
+++ b/common.mk
@@ -213,6 +213,8 @@ showconfig:
 	$(configure_args) \
 	$(ECHO_END)
 
+EXTS_NOTE = -f $(EXTS_MK) $(mflags) RUBY="$(MINIRUBY)" top_srcdir="$(srcdir)" note
+
 exts: build-ext
 
 EXTS_MK = exts.mk
@@ -237,7 +239,10 @@ configure-ext: $(EXTS_MK)
 build-ext: $(EXTS_MK)
 	$(Q)$(MAKE) -f $(EXTS_MK) $(mflags) libdir="$(libdir)" LIBRUBY_EXTS=$(LIBRUBY_EXTS) \
 	    EXTENCS="$(ENCOBJS)" UPDATE_LIBRARIES=no $(EXTSTATIC)
-	$(Q)$(MAKE) -f $(EXTS_MK) $(mflags) RUBY="$(MINIRUBY)" top_srcdir="$(srcdir)" note
+	$(Q)$(MAKE) $(EXTS_NOTE)
+
+exts-note: $(EXTS_MK)
+	$(Q)$(MAKE) $(EXTS_NOTE)
 
 ext/extinit.c: $(srcdir)/template/extinit.c.tmpl
 	$(Q)$(MINIRUBY) $(srcdir)/tool/generic_erb.rb -o $@ -c \