diff --git a/alphastats/DataSet.py b/alphastats/DataSet.py
index 0250a68f..6b8c156c 100644
--- a/alphastats/DataSet.py
+++ b/alphastats/DataSet.py
@@ -148,6 +148,7 @@ def create_matrix(self):
         mat = df.transpose()
         # remove proteins with only zero
         self.mat = mat.loc[:, (mat != 0).any(axis=0)]
+        self.mat = self.mat.astype(float)
         # reset preproccessing info
         self.preprocessing_info = self._save_dataset_info()
         self.preprocessed = False