diff --git a/src/visualization/heatmap_rows.py b/src/visualization/heatmap_rows.py
index 508d8929..4c794665 100644
--- a/src/visualization/heatmap_rows.py
+++ b/src/visualization/heatmap_rows.py
@@ -21,7 +21,7 @@ def getHourlyRowCountHeatmap(dates, hourly_row_count, sensor_name, pid, output_p
 
 
 
-sensor_data = pd.read_csv(snakemake.input[0])
+sensor_data = pd.read_csv(snakemake.input[0], encoding="ISO-8859-1")
 sensor_name = snakemake.params["table"]
 pid = snakemake.params["pid"]