1 files changed, 1 insertions, 1 deletions
diff --git a/math.c b/math.c
index f8d21b1850..332d89916d 100644
--- a/math.c
+++ b/math.c
@@ -128,7 +128,7 @@ math_acos(VALUE obj, VALUE x)
  *  call-seq:
  *     Math.asin(x)    => float
  *  
- *  Computes the arc sine of <i>x</i>. Returns 0..PI.
+ *  Computes the arc sine of <i>x</i>. Returns -{PI/2} .. {PI/2}.
  */
 
 static VALUE