diff --git a/src/distribution/gamma.rs b/src/distribution/gamma.rs
index cbdf6d92..e493d24d 100644
--- a/src/distribution/gamma.rs
+++ b/src/distribution/gamma.rs
@@ -316,7 +316,7 @@ pub fn sample_unchecked<R: Rng + ?Sized>(rng: &mut R, shape: f64, rate: f64) ->
         v *= v * v;
         x *= x;
         let u: f64 = rng.gen();
-        if u < 1.0 - 0.0331 * x * x || u.ln() < 0.5 * x + d * (1.0 - v - v.ln()) {
+        if u < 1.0 - 0.0331 * x * x || u.ln() < 0.5 * x + d * (1.0 - v + v.ln()) {
             return afix * d * v / rate;
         }
     }