diff --git a/tests/codegen/vec-reserve-extend.rs b/tests/codegen/vec-reserve-extend.rs
index d95220104c2..395373ff4f1 100644
--- a/tests/codegen/vec-reserve-extend.rs
+++ b/tests/codegen/vec-reserve-extend.rs
@@ -1,4 +1,6 @@
 // compile-flags: -O
+// ignore-debug
+// (with debug assertions turned on, `assert_unchecked` generates a real assertion)
 
 #![crate_type = "lib"]
 
diff --git a/tests/codegen/vec_pop_push_noop.rs b/tests/codegen/vec_pop_push_noop.rs
index 8bc7b68a816..d9293f2b75d 100644
--- a/tests/codegen/vec_pop_push_noop.rs
+++ b/tests/codegen/vec_pop_push_noop.rs
@@ -1,4 +1,6 @@
 // compile-flags: -O
+// ignore-debug
+// (with debug assertions turned on, `assert_unchecked` generates a real assertion)
 
 #![crate_type = "lib"]