diff --git a/CHANGELOG.md b/CHANGELOG.md
index b477c06..276109b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 <!-- next-header -->
 
 ## [Unreleased] - ReleaseDate
+
+## [0.4.0] - 2021-04-12
 ### Added
 - sawp-modbus: re-export `sawp_flags::Flags` so sawp-flags doesn't need
   to be added to Cargo.toml.
@@ -54,7 +56,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - sawp-modbus: FFI support.
 
 <!-- next-url -->
-[Unreleased]: https://github.com/CybercentreCanada/sawp/compare/sawp-0.3.0...HEAD
+[Unreleased]: https://github.com/CybercentreCanada/sawp/compare/sawp-0.4.0...HEAD
+[0.4.0]: https://github.com/CybercentreCanada/sawp/releases/tag/sawp-0.4.0
 [0.3.0]: https://github.com/CybercentreCanada/sawp/releases/tag/sawp-0.3.0
 [0.2.0]: https://github.com/CybercentreCanada/sawp/releases/tag/sawp-0.2.0
 [0.1.1]: https://github.com/CybercentreCanada/sawp/releases/tag/sawp-0.1.1
diff --git a/Cargo.toml b/Cargo.toml
index 8340149..3221118 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "Security Aware Wire Protocol parsing library"
 readme = "README.md"
@@ -48,7 +48,7 @@ cdylib-link-lines = {version = "0.1.1", optional = true}
 criterion = "0.3"
 
 [dependencies]
-sawp-ffi = { path = "sawp-ffi", version = "^0.3.0", optional = true}
+sawp-ffi = { path = "sawp-ffi", version = "^0.4.0", optional = true}
 nom = "5.1.2"
 
 [[bench]]
diff --git a/README.md b/README.md
index 6f74789..5d5bf1b 100644
--- a/README.md
+++ b/README.md
@@ -39,8 +39,8 @@ types.
 ## Example
 ```
 [dependencies]
-sawp-modbus = "0.3.0"
-sawp = "0.3.0"
+sawp-modbus = "0.4.0"
+sawp = "0.4.0"
 ```
 
 ## FFI Support
diff --git a/sawp-diameter/Cargo.toml b/sawp-diameter/Cargo.toml
index 4e5c511..eb63ec6 100644
--- a/sawp-diameter/Cargo.toml
+++ b/sawp-diameter/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp-diameter"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "SAWP Protocol Parser for Diameter"
 readme = "../README.md"
@@ -21,7 +21,7 @@ include = [
 verbose = ["sawp/verbose"]
 
 [dependencies]
-sawp = { path = "..", version = "^0.3.0"}
+sawp = { path = "..", version = "^0.4.0"}
 nom = "5.1.2"
 num_enum = "0.5.1"
 bitflags = "1.0.4"
diff --git a/sawp-ffi-derive/Cargo.toml b/sawp-ffi-derive/Cargo.toml
index 0cafde4..3bbb53c 100644
--- a/sawp-ffi-derive/Cargo.toml
+++ b/sawp-ffi-derive/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp-ffi-derive"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "Generate cbindgen compatible member accessors for structs and enums"
 readme = "../README.md"
@@ -24,7 +24,7 @@ proc-macro2 = "1.0"
 heck = "0.3"
 
 [dev-dependencies]
-sawp-flags = { path = "../sawp-flags", version = "^0.3.0"}
+sawp-flags = { path = "../sawp-flags", version = "^0.4.0"}
 
 [lib]
 proc-macro = true
diff --git a/sawp-ffi/Cargo.toml b/sawp-ffi/Cargo.toml
index 74c79f8..21b1170 100644
--- a/sawp-ffi/Cargo.toml
+++ b/sawp-ffi/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp-ffi"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "FFI helper macros and traits"
 readme = "../README.md"
@@ -17,8 +17,8 @@ include = [
 ]
 
 [dependencies]
-sawp-ffi-derive = { path = "../sawp-ffi-derive", version = "^0.3.0"}
-sawp-flags = { path = "../sawp-flags", version = "^0.3.0"}
+sawp-ffi-derive = { path = "../sawp-ffi-derive", version = "^0.4.0"}
+sawp-flags = { path = "../sawp-flags", version = "^0.4.0"}
 
 # Override default replacements
 [package.metadata.release]
diff --git a/sawp-file/Cargo.toml b/sawp-file/Cargo.toml
index 08acbd6..8d9da20 100644
--- a/sawp-file/Cargo.toml
+++ b/sawp-file/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp-file"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "SAWP File Format"
 readme = "../README.md"
@@ -18,7 +18,7 @@ include = [
 ]
 
 [dependencies]
-sawp = { path = "..", version = "^0.3.0"}
+sawp = { path = "..", version = "^0.4.0"}
 rmp-serde = "0.14.4"
 serde = "1.0.116"
 serde_derive = "1.0.116"
diff --git a/sawp-flags-derive/Cargo.toml b/sawp-flags-derive/Cargo.toml
index 8b8b42a..3ec68f4 100644
--- a/sawp-flags-derive/Cargo.toml
+++ b/sawp-flags-derive/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp-flags-derive"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "SAWP BitFlags Handling and Storage Derive Macro"
 readme = "../README.md"
diff --git a/sawp-flags/Cargo.toml b/sawp-flags/Cargo.toml
index 7605998..b6cdb6d 100644
--- a/sawp-flags/Cargo.toml
+++ b/sawp-flags/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp-flags"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "SAWP BitFlags Handling and Storage"
 readme = "../README.md"
@@ -17,7 +17,7 @@ include = [
 ]
 
 [dependencies]
-sawp-flags-derive = { path = "../sawp-flags-derive", version = "^0.3.0"}
+sawp-flags-derive = { path = "../sawp-flags-derive", version = "^0.4.0"}
 
 # Override default replacements
 [package.metadata.release]
diff --git a/sawp-json/Cargo.toml b/sawp-json/Cargo.toml
index fe7d164..e6847bf 100644
--- a/sawp-json/Cargo.toml
+++ b/sawp-json/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp-json"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "SAWP Protocol Parser for Json"
 readme = "../README.md"
@@ -21,7 +21,7 @@ include = [
 verbose = ["sawp/verbose"]
 
 [dependencies]
-sawp = { path = "..", version = "^0.3.0"}
+sawp = { path = "..", version = "^0.4.0"}
 serde = "1.0"
 serde_json = "1.0"
 
diff --git a/sawp-modbus/Cargo.toml b/sawp-modbus/Cargo.toml
index 8ef6b80..14a2017 100644
--- a/sawp-modbus/Cargo.toml
+++ b/sawp-modbus/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp-modbus"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "SAWP Protocol Parser for Modbus"
 readme = "../README.md"
@@ -25,9 +25,9 @@ verbose = ["sawp/verbose"]
 cbindgen = {version = "0.15", optional = true}
 
 [dependencies]
-sawp-ffi = { path = "../sawp-ffi", version = "^0.3.0", optional = true}
-sawp-flags = { path = "../sawp-flags", version = "^0.3.0"}
-sawp = { path = "..", version = "^0.3.0"}
+sawp-ffi = { path = "../sawp-ffi", version = "^0.4.0", optional = true}
+sawp-flags = { path = "../sawp-flags", version = "^0.4.0"}
+sawp = { path = "..", version = "^0.4.0"}
 nom = "5.1.2"
 num_enum = "0.5.1"
 
diff --git a/sawp-tftp/Cargo.toml b/sawp-tftp/Cargo.toml
index f0b207b..ba77bce 100644
--- a/sawp-tftp/Cargo.toml
+++ b/sawp-tftp/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sawp-tftp"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Canadian Centre for Cyber Security <sa-sawp@cyber.gc.ca>"]
 description = "SAWP Protocol Parser for TFTP"
 readme = "../README.md"
@@ -18,7 +18,7 @@ include = [
 ]
 
 [dependencies]
-sawp = { path = "..", version = "^0.3.0"}
+sawp = { path = "..", version = "^0.4.0"}
 nom = "5.1.2"
 num_enum = "0.5.1"