diff --git a/Code/python/src/aiRNN/dataloader.py b/Code/python/src/aiRNN/dataloader.py
index 737977a..4993e5e 100644
--- a/Code/python/src/aiRNN/dataloader.py
+++ b/Code/python/src/aiRNN/dataloader.py
@@ -134,7 +134,7 @@ class EvenlySpacedDataset(BaseDataset):
         # Preload all data into memory
         self.data = []
         for fp in self.filepaths:
-            df = pd.read_csv(fp)
+            df = pd.read_csv(fp, dtype={"icao": str, "r": str, "t": str, "timestamp": float, "lat": float, "lon": float, "alt": float, "ias": float})
             n_rows = len(df)
             # Extract windows
             for w in range(n_windows_per_file):
@@ -217,7 +217,7 @@ class EvenlySpacedStreamingDataset(BaseDataset):
 
         # Read only the required rows
         skip = list(set(range(1, start_idx + 1)))
-        df = pd.read_csv(fp, skiprows=skip, nrows=self.window_size * self.step).iloc[::self.step]
+        df = pd.read_csv(fp, skiprows=skip, nrows=self.window_size * self.step, dtype={"icao": str, "r": str, "t": str, "timestamp": float, "lat": float, "lon": float, "alt": float, "ias": float}).iloc[::self.step]
         df = self._modify_df(df)
 
         # Slice into input / decoder-input / targets