diff --git a/lib/macro/Cargo.toml b/lib/macro/Cargo.toml
index c167919..f85dbea 100644
--- a/lib/macro/Cargo.toml
+++ b/lib/macro/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "data-encoding-macro"
-version = "0.1.20"
+version = "0.1.21-git"
 authors = ["Julien Cretin <cretin@google.com>"]
 license = "MIT"
 edition = "2018"
@@ -15,4 +15,4 @@ include = ["Cargo.toml", "LICENSE", "README.md", "src/lib.rs"]
 
 [dependencies]
 data-encoding = { version = "2.11.0", path = "..", default-features = false }
-data-encoding-macro-internal = { version = "0.1.18", path = "internal" }
+data-encoding-macro-internal = { version = "0.1.19-git", path = "internal" }
diff --git a/lib/macro/internal/Cargo.toml b/lib/macro/internal/Cargo.toml
index 513244c..3de3784 100644
--- a/lib/macro/internal/Cargo.toml
+++ b/lib/macro/internal/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "data-encoding-macro-internal"
-version = "0.1.18"
+version = "0.1.19-git"
 authors = ["Julien Cretin <cretin@google.com>"]
 license = "MIT"
 edition = "2018"
@@ -20,6 +20,6 @@ default-features = false
 features = ["alloc"]
 
 [dependencies.syn]
-version = ">= 1, < 3"
+version = ">= 1, < 4"
 default-features = false
 features = ["parsing", "proc-macro"]