diff --git a/README.md b/README.md
index 380df6b..1b8a117 100644
--- a/README.md
+++ b/README.md
@@ -87,6 +87,20 @@ and cleans up unused "flag references".
 It is a Rust reimplementation of
 the [MarshalParser Python module](https://github.com/fedora-python/marshalparser).
 
+### `pyc-zero-mtime`
+
+Accepts `*.pyc`.
+
+This handler sets the internal timestamp in `.pyc` file header to 0,
+and sets the mtime on the corresponding source `.py` file to 0.
+This is intended to be used on [OSTree](https://github.com/ostreedev/ostree)
+systems where mtimes are discarded,
+causing a mismatch between the timestamp embedded in the `.pyc` file
+and the filesystem metadata of the `.py` file.
+
+This handler is not enabled by default and must be explicitly requested
+via `--handlers pyc-zero-mtime`.
+
 ## Notes
 
 This project is inspired by
diff --git a/src/handlers/mod.rs b/src/handlers/mod.rs
index a8e8e31..e7e8610 100644
--- a/src/handlers/mod.rs
+++ b/src/handlers/mod.rs
@@ -176,23 +176,24 @@ impl Stats {
 
 pub type HandlerBoxed = fn(&Rc<options::Config>) -> Box<dyn Processor>;
 
-pub const HANDLERS: &[(&str, HandlerBoxed)] = &[
-    ("ar",      ar::Ar::boxed),
-    ("jar",     jar::Jar::boxed),
-    ("javadoc", javadoc::Javadoc::boxed),
-    ("pyc",     pyc::Pyc::boxed),
+pub const HANDLERS: &[(&str, bool, HandlerBoxed)] = &[
+    ("ar",             true,  ar::Ar::boxed           ),
+    ("jar",            true,  jar::Jar::boxed         ),
+    ("javadoc",        true,  javadoc::Javadoc::boxed ),
+    ("pyc",            true,  pyc::Pyc::boxed         ),
+    ("pyc-zero-mtime", false, pyc::PycZeroMtime::boxed),
 ];
 
 pub fn handler_names() -> Vec<&'static str> {
     HANDLERS.iter()
-        .map(|(name, _)| *name)
+        .map(|(name, _, _)| *name)
         .collect()
 }
 
 pub fn make_handlers(config: &Rc<options::Config>) -> Result<Vec<Box<dyn Processor>>> {
     let mut handlers: Vec<Box<dyn Processor>> = vec![];
 
-    for (name, func) in HANDLERS {
+    for (name, _, func) in HANDLERS {
         if config.handler_names.contains(name) {
             let mut handler = func(config);
             match handler.initialize() {
diff --git a/src/options.rs b/src/options.rs
index 74474cb..10ea963 100644
--- a/src/options.rs
+++ b/src/options.rs
@@ -73,7 +73,7 @@ pub struct Config {
     pub strict_handlers: bool,
 }
 
-fn filter_by_name(name: &str, filter: &[&str]) -> bool {
+fn filter_by_name(name: &str, enabled_by_default: bool, filter: &[&str]) -> bool {
     let mut negative_filter = true;
 
     for f in filter.iter().rev() {
@@ -90,7 +90,7 @@ fn filter_by_name(name: &str, filter: &[&str]) -> bool {
         }
     }
 
-    negative_filter
+    enabled_by_default && negative_filter
 }
 
 pub fn requested_handlers(filter: &[&str]) -> Result<(Vec<&'static str>, bool)> {
@@ -109,8 +109,8 @@ pub fn requested_handlers(filter: &[&str]) -> Result<(Vec<&'static str>, bool)>
 
     let list: Vec<&'static str> = handlers::HANDLERS
         .iter()
-        .filter(|(name, _)| filter_by_name(name, filter))
-        .map(|(name, _)| *name)
+        .filter(|(name, enabled_by_default, _)| filter_by_name(name, *enabled_by_default, filter))
+        .map(|(name, _, _)| *name)
         .collect();
 
     if list.is_empty() {
@@ -213,10 +213,31 @@ mod tests {
 
     #[test]
     fn test_filter_by_name() {
-        assert_eq!(filter_by_name("x", &vec!["x", "y"]), true);
-        assert_eq!(filter_by_name("x", &vec!["x"]), true);
-        assert_eq!(filter_by_name("x", &vec![]), true);
-        assert_eq!(filter_by_name("x", &vec!["-x"]), false);
-        assert_eq!(filter_by_name("x", &vec!["-y"]), true);
+        assert_eq!(filter_by_name("x", true, &vec!["x", "y"]), true);
+        assert_eq!(filter_by_name("x", true, &vec!["x"]), true);
+        assert_eq!(filter_by_name("x", true, &vec![]), true);
+        assert_eq!(filter_by_name("x", true, &vec!["-x"]), false);
+        assert_eq!(filter_by_name("x", true, &vec!["-y"]), true);
+
+        assert_eq!(filter_by_name("x", false, &vec!["x", "y"]), true);
+        assert_eq!(filter_by_name("x", false, &vec!["x"]), true);
+        assert_eq!(filter_by_name("x", false, &vec![]), false);
+        assert_eq!(filter_by_name("x", false, &vec!["-x"]), false);
+        assert_eq!(filter_by_name("x", false, &vec!["-y"]), false);
+    }
+
+    #[test]
+    fn test_requested_handlers() {
+        let (list, strict) = requested_handlers(&vec![]).unwrap();
+        assert_eq!(list, vec!["ar", "jar", "javadoc", "pyc"]);
+        assert_eq!(strict, false);
+
+        let (list, strict) = requested_handlers(&vec!["ar", "pyc-zero-mtime"]).unwrap();
+        assert_eq!(list, vec!["ar", "pyc-zero-mtime"]);
+        assert_eq!(strict, true);
+
+        let (list, strict) = requested_handlers(&vec!["-pyc-zero-mtime"]).unwrap();
+        assert_eq!(list, vec!["ar", "jar", "javadoc", "pyc"]);
+        assert_eq!(strict, true);
     }
 }