diff --git a/proc-macro-definitions/Cargo.toml b/proc-macro-definitions/Cargo.toml
index 5153521..525a6b5 100644
--- a/proc-macro-definitions/Cargo.toml
+++ b/proc-macro-definitions/Cargo.toml
@@ -28,7 +28,7 @@ proc-macro = true
 [dependencies]
 call2-for-syn = "3.0.4"
 debugless-unwrap = "0.0.4"
-heck = "0.3.1"
+heck = "0.5.0"
 lazy_static = "1.4.0"
 quote = "1.0.10"
 proc-macro-crate = "1.0.0"