diff --git a/src/util/format/pixel.rs b/src/util/format/pixel.rs
index a4db217..4ccfe7b 100644
--- a/src/util/format/pixel.rs
+++ b/src/util/format/pixel.rs
@@ -928,13 +928,6 @@ impl fmt::Display for ParsePixelError {
 }
 
 impl error::Error for ParsePixelError {
-    fn description(&self) -> &str {
-        match *self {
-            ParsePixelError::NulError(ref e) => &e.to_string(),
-            ParsePixelError::UnknownFormat => "unknown pixel format",
-        }
-    }
-
     fn cause(&self) -> Option<&dyn error::Error> {
         match *self {
             ParsePixelError::NulError(ref e) => Some(e),