diff --git a/src/fastfield/reader.rs b/src/fastfield/reader.rs
index 3a1a90634..76de5ac7b 100644
--- a/src/fastfield/reader.rs
+++ b/src/fastfield/reader.rs
@@ -85,24 +85,6 @@ impl<Item: FastValue> FastFieldReader<Item> {
         }
     }
 
-    /// Internally `multivalued` also use SingleValue Fast fields.
-    /// It works as follows... A first column contains the list of start index
-    /// for each document, a second column contains the actual values.
-    ///
-    /// The values associated to a given doc, are then
-    ///  `second_column[first_column.get(doc)..first_column.get(doc+1)]`.
-    ///
-    /// Which means single value fast field reader can be indexed internally with
-    /// something different from a `DocId`. For this use case, we want to use `u64`
-    /// values.
-    ///
-    /// See `get_range` for an actual documentation about this method.
-    pub(crate) fn get_range_u64(&self, start: u64, output: &mut [Item]) -> Item {
-        for (i, out) in output.iter_mut().enumerate() {
-            *out = self.get(start + i as u32);
-        }
-    }
-
     /// Fills an output buffer with the fast field values
     /// associated with the `DocId` going from
     /// `start` to `start + output.len()`.