diff --git a/wchar-impl/Cargo.toml b/wchar-impl/Cargo.toml
index ea7d138..0e00dd4 100644
--- a/wchar-impl/Cargo.toml
+++ b/wchar-impl/Cargo.toml
@@ -14,7 +14,11 @@ license = "MIT"
 proc-macro = true
 
 [dependencies]
-proc-macro2 = "0.4"
+proc-macro2 = "1.0"
 proc-macro-hack = "0.5"
-quote = "0.6"
-syn = { version = "0.15", features = ["full"] }
+quote = "1.0"
+
+[dependencies.syn]
+version = "1.0"
+default-features = false
+features = ["derive", "parsing", "proc-macro"]