diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index 7d10f0d..887fa2d 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,5 +1,5 @@
 {
   "git": {
-    "sha1": "8bda3b64daf53f0ed6bb6bee2c767a63c7c477fc"
+    "sha1": "004cfc218e7fbfdbecc4088f9e3fa5061f36cb4d"
   }
 }
diff --git a/Android.bp b/Android.bp
index 9905be3..3051273 100644
--- a/Android.bp
+++ b/Android.bp
@@ -60,19 +60,19 @@
 //   atty-0.2.14
 //   bitflags-1.2.1 "default"
 //   clap-2.33.3 "ansi_term,atty,color,default,strsim,suggestions,vec_map"
-//   heck-0.3.2
+//   heck-0.3.3
 //   lazy_static-1.4.0
-//   libc-0.2.94
+//   libc-0.2.98
 //   proc-macro-error-1.0.4 "default,syn,syn-error"
 //   proc-macro-error-attr-1.0.4
-//   proc-macro2-1.0.26 "default,proc-macro"
+//   proc-macro2-1.0.28 "default,proc-macro"
 //   quote-1.0.9 "default,proc-macro"
 //   strsim-0.8.0
-//   structopt-derive-0.4.14
-//   syn-1.0.71 "clone-impls,default,derive,full,parsing,printing,proc-macro,quote"
+//   structopt-derive-0.4.15
+//   syn-1.0.74 "clone-impls,default,derive,extra-traits,full,parsing,printing,proc-macro,quote"
 //   textwrap-0.11.0
-//   unicode-segmentation-1.7.1
+//   unicode-segmentation-1.8.0
 //   unicode-width-0.1.8 "default"
-//   unicode-xid-0.2.1 "default"
+//   unicode-xid-0.2.2 "default"
 //   vec_map-0.8.2
 //   version_check-0.9.3
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 650afea..117ef2d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# v0.3.22 (2021-07-04)
+
+* Add support for [generics in derive](https://github.com/TeXitoi/structopt/issues/128)
+
 # v0.3.21 (2020-11-30)
 
 * Fixed [another breakage](https://github.com/TeXitoi/structopt/issues/447)
diff --git a/Cargo.toml b/Cargo.toml
index d24c98b..260ef4a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,7 +13,7 @@
 [package]
 edition = "2018"
 name = "structopt"
-version = "0.3.21"
+version = "0.3.22"
 authors = ["Guillaume Pinot <texitoi@texitoi.eu>", "others"]
 description = "Parse command line argument by defining a struct."
 documentation = "https://docs.rs/structopt"
@@ -35,10 +35,14 @@
 package = "paw"
 
 [dependencies.structopt-derive]
-version = "=0.4.14"
+version = "=0.4.15"
 [dev-dependencies.rustversion]
 version = "1"
 
+[dev-dependencies.strum]
+version = "0.20"
+features = ["derive"]
+
 [dev-dependencies.trybuild]
 version = "1.0.5"
 features = ["diff"]
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index fdad9ef..d45ecac 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,6 +1,6 @@
 [package]
 name = "structopt"
-version = "0.3.21"
+version = "0.3.22"
 edition = "2018"
 authors = ["Guillaume Pinot <texitoi@texitoi.eu>", "others"]
 description = "Parse command line argument by defining a struct."
@@ -28,10 +28,11 @@
 
 [dependencies]
 clap = { version = "2.33", default-features = false }
-structopt-derive = { path = "structopt-derive", version = "=0.4.14" }
+structopt-derive = { path = "structopt-derive", version = "=0.4.15" }
 lazy_static = "1.4.0"
 paw_dep = { version = "1", optional = true, package = "paw" }
 
 [dev-dependencies]
 trybuild = { version = "1.0.5", features = ["diff"] }
 rustversion = "1"
+strum = { version = "0.20", features = ["derive"] }
diff --git a/METADATA b/METADATA
index df2195b..40329f0 100644
--- a/METADATA
+++ b/METADATA
@@ -7,13 +7,13 @@
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/structopt/structopt-0.3.21.crate"
+    value: "https://static.crates.io/crates/structopt/structopt-0.3.22.crate"
   }
-  version: "0.3.21"
+  version: "0.3.22"
   license_type: NOTICE
   last_upgrade_date {
-    year: 2020
-    month: 11
-    day: 30
+    year: 2021
+    month: 8
+    day: 9
   }
 }
diff --git a/examples/enum_in_args_with_strum.rs b/examples/enum_in_args_with_strum.rs
new file mode 100644
index 0000000..a045a48
--- /dev/null
+++ b/examples/enum_in_args_with_strum.rs
@@ -0,0 +1,27 @@
+use structopt::StructOpt;
+use strum::{EnumString, EnumVariantNames, VariantNames};
+
+const DEFAULT: &str = "txt";
+
+#[derive(StructOpt, Debug)]
+struct Opt {
+    #[structopt(
+        long,
+        possible_values = Format::VARIANTS,
+        case_insensitive = true,
+        default_value = DEFAULT,
+    )]
+    format: Format,
+}
+
+#[derive(EnumString, EnumVariantNames, Debug)]
+#[strum(serialize_all = "kebab_case")]
+enum Format {
+    Txt,
+    Md,
+    Html,
+}
+
+fn main() {
+    println!("{:?}", Opt::from_args());
+}
diff --git a/examples/example.rs b/examples/example.rs
index 7a9a514..71cc124 100644
--- a/examples/example.rs
+++ b/examples/example.rs
@@ -37,7 +37,7 @@
 
     // An optional list of values, will be `None` if not present on
     // the command line, will be `Some(vec![])` if no argument is
-    // provided (i.e. `--optv`) and will be `Some(Some(String))` if
+    // provided (i.e. `--optv`) and will be `Some(Vec<String>)` if
     // argument list is provided (e.g. `--optv a b c`).
     #[structopt(long)]
     optv: Option<Vec<String>>,
diff --git a/src/lib.rs b/src/lib.rs
index fb4ad85..b6e6b73 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -52,6 +52,7 @@
 //!     - [Flattening subcommands](#flattening-subcommands)
 //! - [Flattening](#flattening)
 //! - [Custom string parsers](#custom-string-parsers)
+//! - [Generics](#generics)
 //!
 //!
 //!
@@ -1053,6 +1054,42 @@
 //! In the `try_from_*` variants, the function will run twice on valid input:
 //! once to validate, and once to parse. Hence, make sure the function is
 //! side-effect-free.
+//!
+//! ## Generics
+//!
+//! Generic structs and enums can be used. They require explicit trait bounds
+//! on any generic types that will be used by the `StructOpt` derive macro. In
+//! some cases, associated types will require additional bounds. See the usage
+//! of `FromStr` below for an example of this.
+//!
+//! ```
+//! # use structopt::StructOpt;
+//! use std::{fmt, str::FromStr};
+//!
+//! // a struct with single custom argument
+//! #[derive(StructOpt)]
+//! struct GenericArgs<T:FromStr> where <T as FromStr>::Err: fmt::Display + fmt::Debug {
+//!     generic_arg_1: String,
+//!     generic_arg_2: String,
+//!     custom_arg_1: T
+//! }
+//! ```
+//!
+//! or
+//!
+//! ```
+//! # use structopt::StructOpt;
+//! // a struct with multiple custom arguments in a substructure
+//! #[derive(StructOpt)]
+//! struct GenericArgs<T:StructOpt> {
+//!     generic_arg_1: String,
+//!     generic_arg_2: String,
+//!     #[structopt(flatten)]
+//!     custom_args: T
+//! }
+//! ```
+
+
 
 // those mains are for a reason
 #![allow(clippy::needless_doctest_main)]
diff --git a/tests/generics.rs b/tests/generics.rs
new file mode 100644
index 0000000..896f98a
--- /dev/null
+++ b/tests/generics.rs
@@ -0,0 +1,137 @@
+
+use structopt::StructOpt;
+
+#[test]
+fn generic_struct_flatten() {
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    struct Inner{
+        pub answer: isize
+    }
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    struct Outer<T:StructOpt>{
+        #[structopt(flatten)]
+        pub inner: T
+    }
+
+    assert_eq!(
+        Outer{inner: Inner{ answer: 42 }},
+        Outer::from_iter(&[ "--answer",  "42" ])
+    )
+}
+
+#[test]
+fn generic_struct_flatten_w_where_clause() {
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    struct Inner{
+        pub answer: isize
+    }
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    struct Outer<T> where T:StructOpt {
+        #[structopt(flatten)]
+        pub inner: T
+    }
+
+    assert_eq!(
+        Outer{inner: Inner{ answer: 42 }},
+        Outer::from_iter(&[ "--answer",  "42" ])
+    )
+}
+
+#[test]
+fn generic_enum() {
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    struct Inner{
+        pub answer: isize
+    }
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    enum GenericEnum<T: StructOpt> {
+
+        Start(T),
+        Stop,
+    }
+
+    assert_eq!(
+        GenericEnum::Start(Inner{answer: 42}),
+        GenericEnum::from_iter(&[ "test", "start", "42" ])
+    )
+
+}
+
+#[test]
+fn generic_enum_w_where_clause() {
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    struct Inner{
+        pub answer: isize
+    }
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    enum GenericEnum<T> where T: StructOpt {
+
+        Start(T),
+        Stop,
+    }
+
+    assert_eq!(
+        GenericEnum::Start(Inner{answer: 42}),
+        GenericEnum::from_iter(&[ "test", "start", "42" ])
+    )
+
+}
+
+#[test]
+fn generic_w_fromstr_trait_bound() {
+
+    use std::{fmt, str::FromStr};
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    struct Opt<T> where T:FromStr, <T as FromStr>::Err: fmt::Debug + fmt::Display
+    {
+        answer: T
+    }
+
+    assert_eq!(
+        Opt::<isize>{answer:42},
+        Opt::<isize>::from_iter([& "--answer", "42" ])
+    )
+}
+
+#[test]
+fn generic_wo_trait_bound() {
+
+    use std::time::Duration;
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    struct Opt<T> {
+        answer: isize,
+        #[structopt(skip)]
+        took: Option<T>
+    }
+
+    assert_eq!(
+        Opt::<Duration>{answer:42,took:None},
+        Opt::<Duration>::from_iter([& "--answer", "42" ])
+    )
+}
+
+#[test]
+fn generic_where_clause_w_trailing_comma() {
+
+    use std::{fmt, str::FromStr};
+
+    #[derive(StructOpt,PartialEq,Debug)]
+    struct Opt<T> where T:FromStr, <T as FromStr>::Err: fmt::Debug + fmt::Display {
+        pub answer: T
+    }
+
+    assert_eq!(
+        Opt::<isize>{answer:42},
+        Opt::<isize>::from_iter(&[ "--answer", "42" ])
+    )
+}