diff --git a/io.c b/io.c
index 069b4fb1d2..fde0ac94d5 100644
--- a/io.c
+++ b/io.c
@@ -10063,8 +10063,8 @@ argf_write(VALUE argf, VALUE str)
  */
 
 /*
-* Document-class: EOFError
-*
+ * Document-class: EOFError
+ *
  * Raised by some IO operations when reaching the end of file. Many IO
  * methods exist in two forms,
  *
diff --git a/string.c b/string.c
index b1ada5ca2b..6e210a2075 100644
--- a/string.c
+++ b/string.c
@@ -4690,7 +4690,7 @@ rb_str_capitalize(VALUE str)
 
 /*
  *  call-seq:
-*     str.swapcase!   -> str or nil
+ *     str.swapcase!   -> str or nil
  *
  *  Equivalent to <code>String#swapcase</code>, but modifies the receiver in
  *  place, returning <i>str</i>, or <code>nil</code> if no changes were made.