diff --git a/src/codec/encoder/audio.rs b/src/codec/encoder/audio.rs
index 8e07a59..215f8b2 100644
--- a/src/codec/encoder/audio.rs
+++ b/src/codec/encoder/audio.rs
@@ -193,6 +193,12 @@ impl Deref for Encoder {
     }
 }
 
+impl DerefMut for Encoder {
+    fn deref_mut(&mut self) -> &mut <Self as Deref>::Target {
+        &mut self.0
+    }
+}
+
 impl AsRef<Context> for Encoder {
     fn as_ref(&self) -> &Context {
         self
diff --git a/src/codec/encoder/subtitle.rs b/src/codec/encoder/subtitle.rs
index 33ac17c..0bbb346 100644
--- a/src/codec/encoder/subtitle.rs
+++ b/src/codec/encoder/subtitle.rs
@@ -108,6 +108,12 @@ impl Deref for Encoder {
     }
 }
 
+impl DerefMut for Encoder {
+    fn deref_mut(&mut self) -> &mut <Self as Deref>::Target {
+        &mut self.0
+    }
+}
+
 impl AsRef<Context> for Encoder {
     fn as_ref(&self) -> &Context {
         self