diff --git a/impl/Cargo.toml b/impl/Cargo.toml
index bc95d60..5f75f33 100644
--- a/impl/Cargo.toml
+++ b/impl/Cargo.toml
@@ -12,6 +12,6 @@ proc-macro = true
 
 [dependencies]
 proc-macro-hack = "0.5"
-proc-macro2 = "0.4"
-quote = "0.6"
-syn = "0.15"
+proc-macro2 = "1.0"
+quote = "1.0"
+syn = "1.0"