diff --git a/matlab/pm3.m b/matlab/pm3.m
index 52ea8ff80..3c6857c62 100644
--- a/matlab/pm3.m
+++ b/matlab/pm3.m
@@ -87,7 +87,8 @@ filter_step_ahead_indicator=0;
 filter_covar_indicator=0;
 
 for file = 1:ifil
-    load([DirectoryName '/' M_.fname var_type int2str(file)]);
+    loaded_file=load([DirectoryName '/' M_.fname var_type int2str(file)]);
+    stock=loaded_file.stock;
     if strcmp(var_type,'_filter_step_ahead')
         if file==1 %on first run, initialize variable for storing filter_step_ahead
             stock1_filter_step_ahead=NaN(n1,n2,B,length(options_.filter_step_ahead));