diff --git a/matlab/check_posterior_sampler_options.m b/matlab/check_posterior_sampler_options.m
index 220017686..7f242fc8e 100644
--- a/matlab/check_posterior_sampler_options.m
+++ b/matlab/check_posterior_sampler_options.m
@@ -304,10 +304,10 @@ if init,
             %     options_.mh_posterior_mode_estimation = 0;
             % this is done below, but perhaps preprocessing should do this?
             
-            if ~isfield(posterior_sampler_options,'mode'),
-                posterior_sampler_options.mode = [];
-            else % multimodal case
+            if ~isempty(posterior_sampler_options.mode)
+                % multimodal case
                 posterior_sampler_options.rotated = 1;
+                posterior_sampler_options.WR=[];
             end
             %     posterior_sampler_options = set_default_option(posterior_sampler_options,'mode_files',[]);
             
diff --git a/matlab/global_initialization.m b/matlab/global_initialization.m
index 6f8f5d1c7..88b40c165 100644
--- a/matlab/global_initialization.m
+++ b/matlab/global_initialization.m
@@ -476,6 +476,7 @@ options_.posterior_sampler_options.slice.slice_initialize_with_mode=0;
 options_.posterior_sampler_options.slice.use_mh_covariance_matrix=0;
 options_.posterior_sampler_options.slice.WR=[];
 options_.posterior_sampler_options.slice.mode_files=[];
+options_.posterior_sampler_options.slice.mode=[];
 options_.posterior_sampler_options.slice.initial_step_size=0.8;
 % Independent Metropolis-Hastings
 options_.posterior_sampler_options.imh.proposal_distribution = 'rand_multivariate_normal';