diff --git a/particle.py b/particle.py
index 909536b..14325a5 100644
--- a/particle.py
+++ b/particle.py
@@ -320,9 +320,9 @@ class Trajectories:
         return self._slice(slice_part=sl[0],slice_time=sl[1])
 
     @classmethod
-    def from_mat(cls,file,unraveled=False,select_col=None):
+    def from_mat(cls,file,unraveled=False,select_col=None,varpp='pp'):
         from .helper import load_mat
-        pp = load_mat(file,'pp',cast_integer=False) # int casting is expensive and useless on potentially large array
+        pp = load_mat(file,varpp,cast_integer=False) # int casting is expensive and useless on potentially large array
         col,time,ccinfo = load_mat(file,['colpy','time','ccinfo'],cast_integer=True)
         period = [None,None,None]
         if bool(ccinfo['xperiodic']): period[0]=ccinfo['b']
@@ -608,4 +608,4 @@ def translate_circular(pp,col,translation,bounds,axis=0):
     L = bounds[2*axis+1]
     keys = ('x','y','z')
     pp[col[keys[axis]],:,:] = (pp[col[keys[axis]],:,:]+translation)%L
-    return pp
\ No newline at end of file
+    return pp