diff --git a/src/bbp.rs b/src/bbp.rs
index 5733371..a38ef2b 100644
--- a/src/bbp.rs
+++ b/src/bbp.rs
@@ -45,8 +45,8 @@ fn expm(p: f64, ak: f64) -> f64 {
     const NTP : usize = 25;
 
     lazy_static! {
-        static ref TP : Vec<f64> = {
-            let mut v = vec![1f64; NTP];
+        static ref TP: [f64; NTP] = {
+            let mut v = [1f64; NTP];
 
             for i in 1..NTP {
                 v[i] = 2.0 * v[i - 1];