diff --git a/crates/h264/src/synth_tests.rs b/crates/h264/src/synth_tests.rs
index 24a104cf..a2f9988a 100644
--- a/crates/h264/src/synth_tests.rs
+++ b/crates/h264/src/synth_tests.rs
@@ -116,14 +116,16 @@ fn avcc_rejects_a_valid_picture_slice_without_starting_a_picture() {
         },
         false,
     );
-    let mut avcc = vec![1, 66, 0, 30, 0xff, 0xe2];
-    for nal in [&sequence[4..], &slice[4..]] {
+    let mut avcc = vec![1, 66, 0, 30, 0xff, 0xe1];
+    for nal in [&sequence[4..]] {
         avcc.extend_from_slice(&(nal.len() as u16).to_be_bytes());
         avcc.extend_from_slice(nal);
     }
-    avcc.push(1);
+    avcc.push(2);
     avcc.extend_from_slice(&((picture.len() - 4) as u16).to_be_bytes());
     avcc.extend_from_slice(&picture[4..]);
+    avcc.extend_from_slice(&((slice.len() - 4) as u16).to_be_bytes());
+    avcc.extend_from_slice(&slice[4..]);
 
     let mut decoder = Decoder::with_threads(1);
     assert!(decoder.configure_avcc(&avcc).is_err());
diff --git a/crates/hevc/src/synth_tests.rs b/crates/hevc/src/synth_tests.rs
index 7baf7b49..4d044a3d 100644
--- a/crates/hevc/src/synth_tests.rs
+++ b/crates/hevc/src/synth_tests.rs
@@ -700,5 +700,6 @@ fn hvcc_rejects_a_valid_picture_slice_without_starting_a_picture() {
 
     let mut decoder = Decoder::with_threads(1);
     assert!(decoder.configure_hvcc(&hvcc).is_err());
+    assert!(decoder.flush().is_empty());
     assert_eq!(decoder.stats().pictures, 0);
 }