1 files changed, 1 insertions, 1 deletions
diff --git a/lib/cmath.rb b/lib/cmath.rb
index 14c2a9fce6..d613a3f6f9 100644
--- a/lib/cmath.rb
+++ b/lib/cmath.rb
@@ -147,7 +147,7 @@ module CMath
   ##
   # returns the principal value of the cube root of +z+
   def cbrt(z)
-    Complex(z) ** (1.0/3)
+    z ** (1.0/3)
   end
 
   ##