diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 201732d274ebf4..38a5a15fb5fdd0 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -40,7 +40,7 @@ def quote
 end
 
 ##
-# mkmf.rb is used by Ruby C extensions to generate a Makefile which will
+# \Module \MakeMakefile is used by Ruby C extensions to generate a Makefile which will
 # correctly compile and link the C extension to Ruby and a third-party
 # library.
 module MakeMakefile
diff --git a/lib/prism/translation/ruby_parser.rb b/lib/prism/translation/ruby_parser.rb
index a33ea2306c1967..1fb0e278462eeb 100644
--- a/lib/prism/translation/ruby_parser.rb
+++ b/lib/prism/translation/ruby_parser.rb
@@ -4,7 +4,7 @@
 begin
   require "sexp"
 rescue LoadError
-  warn(%q{Error: Unable to load sexp. Add `gem "sexp"` to your Gemfile.})
+  warn(%q{Error: Unable to load sexp. Add `gem "sexp_processor"` to your Gemfile.})
   exit(1)
 end