diff --git a/Cargo.lock b/Cargo.lock
index 35301df..5cff651 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -608,6 +608,7 @@ name = "sheep_cli"
 version = "0.3.0"
 dependencies = [
  "clap 2.32.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "glob 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.20.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "oxipng 2.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "png 0.15.0 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/sheep/src/format/amethyst.rs b/sheep/src/format/amethyst.rs
index 4988094..4d7295b 100644
--- a/sheep/src/format/amethyst.rs
+++ b/sheep/src/format/amethyst.rs
@@ -19,8 +19,13 @@ pub struct SerializedSpriteSheet {
     pub sprites: Vec<SpritePosition>,
 }
 
+#[derive(Clone, Debug, PartialEq, Serialize)]
+pub enum Wrapper<T> {
+    List(T),
+}
+
 impl Format for AmethystFormat {
-    type Data = SerializedSpriteSheet;
+    type Data = Wrapper<SerializedSpriteSheet>;
     type Options = ();
 
     fn encode(
@@ -39,10 +44,10 @@ impl Format for AmethystFormat {
             })
             .collect::<Vec<SpritePosition>>();
 
-        SerializedSpriteSheet {
+        Wrapper::List(SerializedSpriteSheet {
             texture_width: dimensions.0 as f32,
             texture_height: dimensions.1 as f32,
             sprites: sprite_positions,
-        }
+        })
     }
 }
diff --git a/sheep_cli/Cargo.toml b/sheep_cli/Cargo.toml
index 93d02f3..51c10ce 100644
--- a/sheep_cli/Cargo.toml
+++ b/sheep_cli/Cargo.toml
@@ -23,6 +23,7 @@ clap = "2.32"
 ron = "0.4"
 oxipng = "2.2"
 png = "0.15"
+glob = "0.3"
 
 [[bin]]
 name = "sheep"
diff --git a/sheep_cli/src/main.rs b/sheep_cli/src/main.rs
index 78d4f91..9471d09 100644
--- a/sheep_cli/src/main.rs
+++ b/sheep_cli/src/main.rs
@@ -1,15 +1,18 @@
 extern crate clap;
+extern crate glob;
 extern crate image;
 extern crate ron;
 extern crate serde;
 extern crate sheep;
 
 use clap::{App, AppSettings, Arg, SubCommand};
+use glob::glob;
 use serde::Serialize;
 use sheep::{
     AmethystFormat, AmethystNamedFormat, InputSprite, MaxrectsOptions, MaxrectsPacker,
     SimplePacker, SpriteSheet,
 };
+use std::path::{PathBuf, Path};
 use std::str::FromStr;
 use std::{fs::File, io::prelude::*};
 
@@ -93,7 +96,16 @@ fn main() {
         ("pack", Some(matches)) => {
             let input = matches
                 .values_of("INPUT")
-                .map(|values| values.map(|it| String::from(it)).collect::<Vec<String>>())
+                .map(|values| {
+                    values
+                        .flat_map(|path_pattern| {
+                            glob(path_pattern)
+                                .expect("Invalid path pattern")
+                                .map(|path| path.expect("Invalid path"))
+                                .collect::<Vec<PathBuf>>()
+                        })
+                        .collect::<Vec<PathBuf>>()
+                })
                 .unwrap_or(Vec::new());
 
             let out = matches
@@ -171,12 +183,11 @@ fn main() {
     }
 }
 
-fn get_filenames(input: &[String]) -> Vec<String> {
+fn get_filenames(input: &[PathBuf]) -> Vec<String> {
     input
         .iter()
         .map(|path| {
-            std::path::PathBuf::from(&path)
-                .file_stem()
+            path.file_stem()
                 .and_then(|name| name.to_str())
                 .map(|name| String::from_str(name).expect("could not parse string from file name"))
                 .expect("Failed to extract file name")
@@ -184,7 +195,10 @@ fn get_filenames(input: &[String]) -> Vec<String> {
         .collect()
 }
 
-fn load_images(input: &[String]) -> Vec<InputSprite> {
+fn load_images<T>(input: &[T]) -> Vec<InputSprite>
+where
+    T: AsRef<Path>,
+{
     input
         .iter()
         .map(|path| {