diff --git a/src/filters.rs b/src/filters.rs
index 31ffa75b8..fd00a1f48 100644
--- a/src/filters.rs
+++ b/src/filters.rs
@@ -475,7 +475,22 @@ pub fn sort(input: &Value, args: &[Value]) -> FilterResult {
     Ok(Value::Array(sorted))
 }
 
-// TODO sort_natural
+pub fn sort_natural(input: &Value, args: &[Value]) -> FilterResult {
+    try!(check_args_len(args, 0, 0));
+
+    // TODO optional property parameter
+
+    let array = input
+        .as_array()
+        .ok_or_else(|| InvalidType("Array expected".to_owned()))?;
+    let mut sorted: Vec<_> = array
+        .iter()
+        .map(|v| (v.to_string().to_lowercase(), v.clone()))
+        .collect();
+    sorted.sort_by(|a, b| a.partial_cmp(b).unwrap_or(cmp::Ordering::Equal));
+    let result = sorted.into_iter().map(|(_, v)| v).collect();
+    Ok(Value::Array(result))
+}
 
 /// Removes any duplicate elements in an array.
 ///
@@ -1286,6 +1301,22 @@ mod tests {
         assert_eq!(result.unwrap(), tos!("a,1,c"));
     }
 
+    #[test]
+    fn unit_sort() {
+        let input = &Array(vec![tos!("Z"), tos!("b"), tos!("c"), tos!("a")]);
+        let args = &[];
+        let desired_result = Array(vec![tos!("Z"), tos!("a"), tos!("b"), tos!("c")]);
+        assert_eq!(unit!(sort, input, args), desired_result);
+    }
+
+    #[test]
+    fn unit_sort_natural() {
+        let input = &Array(vec![tos!("Z"), tos!("b"), tos!("c"), tos!("a")]);
+        let args = &[];
+        let desired_result = Array(vec![tos!("a"), tos!("b"), tos!("c"), tos!("Z")]);
+        assert_eq!(unit!(sort_natural, input, args), desired_result);
+    }
+
     #[test]
     fn unit_last() {
         assert_eq!(unit!(last,
diff --git a/src/main.rs b/src/main.rs
index 02277087d..2969ec875 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -43,7 +43,7 @@ fn load_yaml(path: &path::Path) -> Result<liquid::Value> {
 }
 
 #[cfg(not(feature = "serde_yaml"))]
-fn load_yaml(path: &path::Path) -> Result<liquid::Value> {
+fn load_yaml(_path: &path::Path) -> Result<liquid::Value> {
     bail!("yaml is unsupported");
 }
 
@@ -54,7 +54,7 @@ fn load_json(path: &path::Path) -> Result<liquid::Value> {
 }
 
 #[cfg(not(feature = "serde_json"))]
-fn load_json(path: &path::Path) -> Result<liquid::Value> {
+fn load_json(_path: &path::Path) -> Result<liquid::Value> {
     bail!("json is unsupported");
 }
 
diff --git a/src/template.rs b/src/template.rs
index e5597619c..549c780f7 100644
--- a/src/template.rs
+++ b/src/template.rs
@@ -43,6 +43,7 @@ impl Renderable for Template {
         context.maybe_add_filter("size", Box::new(filters::size));
         context.maybe_add_filter("slice", Box::new(filters::slice));
         context.maybe_add_filter("sort", Box::new(filters::sort));
+        context.maybe_add_filter("sort_natural", Box::new(filters::sort_natural));
         context.maybe_add_filter("split", Box::new(filters::split));
         context.maybe_add_filter("strip", Box::new(filters::strip));
         context.maybe_add_filter("strip_html", Box::new(filters::strip_html));