diff --git a/doc/tuto_kernel_overview.rst b/doc/tuto_kernel_overview.rst
index dfb7fb3f..da19803b 100644
--- a/doc/tuto_kernel_overview.rst
+++ b/doc/tuto_kernel_overview.rst
@@ -133,7 +133,7 @@ Various constrains can be applied to the parameters of a kernel
     * ``constrain_fixed`` to fix the value of a parameter (the value will not be modified during optimisation)
     * ``constrain_positive`` to make sure the parameter is greater than 0.
     * ``constrain_bounded`` to impose the parameter to be in a given range.
-    * ``tie_param`` to impose the value of two (or more) parameters to be equal.
+    * ``tie_params`` to impose the value of two (or more) parameters to be equal.
 
 When calling one of these functions, the parameters to constrain can either by specified by a regular expression that matches its name or by a number that corresponds to the rank of the parameter. Here is an example ::
 
@@ -146,7 +146,7 @@ When calling one of these functions, the parameters to constrain can either by s
 
     k.constrain_positive('var')
     k.constrain_fixed(np.array([1]),1.75)
-    k.tie_param('len')
+    k.tie_params('len')
     k.unconstrain('white')
     k.constrain_bounded('white',lower=1e-5,upper=.5)
     print k