diff --git a/ext/io/wait/depend b/ext/io/wait/depend
index 70317b1497..b847138296 100644
--- a/ext/io/wait/depend
+++ b/ext/io/wait/depend
@@ -1,5 +1,4 @@
 # AUTOGENERATED DEPENDENCIES START
-# wait.o: $(hdrdir)/ruby/assert.h # not in 2.6
 wait.o: $(RUBY_EXTCONF_H)
 wait.o: $(arch_hdrdir)/ruby/config.h
 wait.o: $(hdrdir)/ruby.h