diff --git a/index-scheduler/src/index_mapper/index_map.rs b/index-scheduler/src/index_mapper/index_map.rs
index d250ba02a..f8080d23b 100644
--- a/index-scheduler/src/index_mapper/index_map.rs
+++ b/index-scheduler/src/index_mapper/index_map.rs
@@ -1,6 +1,3 @@
-/// the map size to use when we don't succeed in reading it in indexes.
-const DEFAULT_MAP_SIZE: usize = 10 * 1024 * 1024 * 1024; // 10 GiB
-
 use std::collections::BTreeMap;
 use std::path::Path;
 use std::time::Duration;
@@ -235,7 +232,7 @@ impl IndexMap {
         enable_mdb_writemap: bool,
         map_size_growth: usize,
     ) {
-        let map_size = index.map_size().unwrap_or(DEFAULT_MAP_SIZE) + map_size_growth;
+        let map_size = index.map_size() + map_size_growth;
         let closing_event = index.prepare_for_closing();
         let generation = self.next_generation();
         self.unavailable.insert(
@@ -387,7 +384,7 @@ mod tests {
 
     fn assert_index_size(index: Index, expected: usize) {
         let expected = clamp_to_page_size(expected);
-        let index_map_size = index.map_size().unwrap();
+        let index_map_size = index.map_size();
         assert_eq!(index_map_size, expected);
     }
 }
diff --git a/milli/src/index.rs b/milli/src/index.rs
index 4b15820f6..bd4e5ec2f 100644
--- a/milli/src/index.rs
+++ b/milli/src/index.rs
@@ -308,8 +308,8 @@ impl Index {
     ///
     /// This value is the maximum between the map size passed during the opening of the index
     /// and the on-disk size of the index at the time of opening.
-    pub fn map_size(&self) -> Result<usize> {
-        Ok(self.env.info().map_size) // TODO remove Result
+    pub fn map_size(&self) -> usize {
+        self.env.info().map_size
     }
 
     pub fn copy_to_path<P: AsRef<Path>>(&self, path: P, option: CompactionOption) -> Result<File> {