diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 8cb4524824..03984b4d2e 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -1211,6 +1211,7 @@ RUBY_EXTERN VALUE rb_cNameErrorMesg;
 RUBY_EXTERN VALUE rb_cNilClass;
 RUBY_EXTERN VALUE rb_cNumeric;
 RUBY_EXTERN VALUE rb_cProc;
+RUBY_EXTERN VALUE rb_cRandom;
 RUBY_EXTERN VALUE rb_cRange;
 RUBY_EXTERN VALUE rb_cRational;
 RUBY_EXTERN VALUE rb_cComplex;