diff --git a/Cargo.toml b/Cargo.toml
index 114af93..7cd3fca 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -39,6 +39,7 @@
 unicode-xid = "0.1"
 
 [dev-dependencies]
+colored = "1.7"
 rayon = "1.0"
 regex = "1.0"
 walkdir = "2.1"
diff --git a/tests/zzz_stable.rs b/tests/zzz_stable.rs
new file mode 100644
index 0000000..87bac22
--- /dev/null
+++ b/tests/zzz_stable.rs
@@ -0,0 +1,23 @@
+#![cfg(syn_disable_nightly_tests)]
+
+extern crate colored;
+
+use colored::Colorize;
+
+const MSG: &str = "
+‖
+‖   WARNING:
+‖   This is not a nightly compiler so not all tests were able to
+‖   run. Syn includes tests that compare Syn's parser against the
+‖   compiler's parser, which requires access to unstable libsyntax
+‖   data structures and a nightly compiler.
+‖
+";
+
+#[test]
+fn notice() {
+    panic!(MSG
+        .replace("WARNING", &"WARNING".bold().to_string())
+        .yellow()
+        .to_string());
+}