diff --git a/src/digest.rs b/src/digest.rs
index a468b8bec..c7f4ff742 100644
--- a/src/digest.rs
+++ b/src/digest.rs
@@ -419,9 +419,9 @@ pub mod incremental_x4 {
             // Pad the input to the length of 4
             let data = [
                 input[0],
-                if N > 1 { input[1] } else { &[] },
-                if N > 2 { input[2] } else { &[] },
-                if N > 3 { input[3] } else { &[] },
+                if N > 1 { input[1] } else { &input[0] },
+                if N > 2 { input[2] } else { &input[0] },
+                if N > 3 { input[3] } else { &input[0] },
             ];
             self.state.absorb_final(data);
         }