diff --git a/Makefile b/Makefile
index 7544b38..85b2950 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,6 @@
 RUST_CHANNEL ?= nightly
 
-CRATES = matches show text_writer triable return_if_ok
-
-# FIXME: Make this unconditional when 1.8 hits the stable channel.
-# ref_filter_map uses Ref::map which is stable since 1.8
-ifneq "$(RUST_CHANNEL)" "stable"
-    CRATES += ref_filter_map
-endif
+CRATES = matches show text_writer triable return_if_ok ref_filter_map
 
 ifeq "$(RUST_CHANNEL)" "nightly"
     CRATES += zip_longest