diff --git a/crates/functions/src/stat/distributions.rs b/crates/functions/src/stat/distributions.rs
index a27c5399c..7acc798ec 100644
--- a/crates/functions/src/stat/distributions.rs
+++ b/crates/functions/src/stat/distributions.rs
@@ -379,7 +379,7 @@ pub(super) fn f_inv(a: &[Arg], _: C) -> R<Value> {
     if p == 0.0 {
         return num_val(0.0);
     }
-    let value = if p <= 0.5 { invert(|x| f_cdf(x, d1, d2), p, 0.0, 1.0, 1e60) } else { invert(|x| f_upper(x, d1, d2), 1.0 - p, 0.0, 1.0, 1e60) };
+    let value = if p < 0.5 { invert(|x| f_cdf(x, d1, d2), p, 0.0, 1.0, 1e60) } else { invert(|x| f_upper(x, d1, d2), 1.0 - p, 0.0, 1.0, 1e60) };
     num_val(value)
 }