diff --git a/src/solvers.rs b/src/solvers.rs
index af84b21..1090c17 100644
--- a/src/solvers.rs
+++ b/src/solvers.rs
@@ -133,6 +133,7 @@ pub fn unsorted<Weight, Time, Interval, InputContainer>(
   let mut memoization = {
     let mut m: Vec<Weight> = Vec::with_capacity(intervals.len());
     if let Some(i) = intervals.get(0) { m.push(i.weight()); }
+    unsafe { m.set_len(intervals.len()) }
     m
   };
 
@@ -200,4 +201,4 @@ mod tests {
     assert_eq!(optimal_set[0].end,    128);
     assert_eq!(optimal_set[0].weight, 15);
   }
-}
\ No newline at end of file
+}