diff --git a/pyerrors/input/pandas.py b/pyerrors/input/pandas.py
index 24296781..867554ae 100644
--- a/pyerrors/input/pandas.py
+++ b/pyerrors/input/pandas.py
@@ -104,7 +104,7 @@ def deserialize_df(df, auto_gamma=False):
             if df[column][0].startswith(b"\x1f\x8b\x08\x00"):
                 df[column] = df[column].transform(lambda x: gzip.decompress(x).decode('utf-8'))
         if isinstance(df[column][0], str):
-            if df[column][0][:20] == '{"program":"pyerrors':
+            if '"program":' in df[column][0][:20]:
                 df[column] = df[column].transform(lambda x: import_json_string(x, verbose=False))
                 if auto_gamma is True:
                     df[column].apply(lambda x: x.gamma_method())