diff --git a/boring/src/x509/mod.rs b/boring/src/x509/mod.rs
index 50750d66..30a4b2b8 100644
--- a/boring/src/x509/mod.rs
+++ b/boring/src/x509/mod.rs
@@ -601,7 +601,7 @@ impl X509Ref {
                 0,
                 std::ptr::null_mut(),
             ))
-            .map(|n| n != 0)
+            .map(|n| n == 1)
         }
     }