diff --git a/core/storage/pager.rs b/core/storage/pager.rs
index 7d70cb427..361525510 100644
--- a/core/storage/pager.rs
+++ b/core/storage/pager.rs
@@ -1422,7 +1422,7 @@ impl Pager {
 
                     // Reserve 2 slots for the trunk page header which is 8 bytes or 2*LEAF_ENTRY_SIZE
                     let max_free_list_entries =
-                        (self.usable_space() / LEAF_ENTRY_SIZE) - RESERVED_SLOTS;
+                        (header.usable_space() / LEAF_ENTRY_SIZE) - RESERVED_SLOTS;
 
                     if number_of_leaf_pages < max_free_list_entries as u32 {
                         turso_assert!(
diff --git a/core/storage/sqlite3_ondisk.rs b/core/storage/sqlite3_ondisk.rs
index fae5f2ea0..7d3086027 100644
--- a/core/storage/sqlite3_ondisk.rs
+++ b/core/storage/sqlite3_ondisk.rs
@@ -276,6 +276,10 @@ impl DatabaseHeader {
     const _CHECK: () = {
         assert!(Self::SIZE == 100);
     };
+
+    pub fn usable_space(self) -> usize {
+        (self.page_size.get() as usize) - (self.reserved_space as usize)
+    }
 }
 
 impl Default for DatabaseHeader {