diff --git a/pysegcnn/core/trainer.py b/pysegcnn/core/trainer.py
index cfdc4b4baf7546a05a9d1e95a54c4d31752fc2aa..2d97f16d7fdf38de2f2f8d1e32260fc389c36c98 100644
--- a/pysegcnn/core/trainer.py
+++ b/pysegcnn/core/trainer.py
@@ -2730,7 +2730,7 @@ class NetworkInference(BaseConfig):
                 ['{}'.format(mstate.name) for mstate in self.state_files]))
 
             # iterate over the individual models
-            df = pd.DataFrame()
+            df = pd.DataFrame(dtype=float)
             for name, output in inference.items():
                 # classification report DataFrame for all individual models
                 df = pd.concat((df, df))