diff --git a/src/brainreg/utils/misc.py b/src/brainreg/utils/misc.py
index ef3efdd..b967766 100644
--- a/src/brainreg/utils/misc.py
+++ b/src/brainreg/utils/misc.py
@@ -49,4 +49,4 @@ def safe_pandas_concat(df1: pd.DataFrame, df2: pd.DataFrame) -> pd.DataFrame:
     elif df1.empty and df2.empty:
         return pd.DataFrame(columns=df1.columns)
     else:
-        return pd.concat([df1, df2])
+        return pd.concat([df1, df2], ignore_index=True)
diff --git a/src/brainreg/utils/volume.py b/src/brainreg/utils/volume.py
index 3409286..6dbed1a 100644
--- a/src/brainreg/utils/volume.py
+++ b/src/brainreg/utils/volume.py
@@ -12,6 +12,8 @@
 import pandas as pd
 from brainglobe_utils.pandas.misc import initialise_df
 
+from .misc import safe_pandas_concat
+
 
 class UnknownAtlasValue(Exception):
     pass
@@ -100,7 +102,7 @@ def add_structure_volume_to_df(
             "total_volume_mm3": [left_volume + right_volume],
         }
     )
-    df = pd.concat([df, df_new_row], ignore_index=True)
+    df = safe_pandas_concat(df, df_new_row)
     return df