diff --git a/interfaces/matlab/toolbox/importPhase.m b/interfaces/matlab/toolbox/importPhase.m
index c3456c904..363b70d0c 100644
--- a/interfaces/matlab/toolbox/importPhase.m
+++ b/interfaces/matlab/toolbox/importPhase.m
@@ -1,6 +1,7 @@
 function s = importPhase(file, name)
 % IMPORTPHASE  Import a phase from a CTI file
 % s = importPhase(file, name)
+% Deprecated. To be removed after Cantera 2.3.
 % See :ref:`sec-phases`.
 %
 % See also: :mat:func:`Solution`
@@ -13,6 +14,7 @@ function s = importPhase(file, name)
 %     Instance of class :mat:func:`Solution`
 %
 
+warning('This function is deprecated and will be removed after Cantera 2.3. Use Solution instead');
 if nargin == 1
     s = Solution(file);
 elseif nargin == 2