diff --git a/swf/src/avm1/read.rs b/swf/src/avm1/read.rs
index 997fd7b1d..9b4b6c83a 100644
--- a/swf/src/avm1/read.rs
+++ b/swf/src/avm1/read.rs
@@ -404,6 +404,19 @@ pub mod tests {
         }
     }
 
+    /// Ensure that we return an error on invalid data.
+    #[test]
+    fn read_parse_error() {
+        let action_bytes = [0xff, 0xff, 0xff, 0x00, 0x00];
+        let mut reader = Reader::new(&action_bytes[..], 5);
+        match reader.read_action() {
+            Err(crate::error::Error::Avm1ParseError { .. }) => (),
+            result => {
+                panic!("Expected Avm1ParseError, got {:?}", result);
+            }
+        }
+    }
+
     #[test]
     fn read_define_function() {
         // Ensure we read a function properly along with the function data.
diff --git a/swf/src/read.rs b/swf/src/read.rs
index c6838030b..2c4cd1616 100644
--- a/swf/src/read.rs
+++ b/swf/src/read.rs
@@ -3136,4 +3136,17 @@ pub mod tests {
             assert_eq!(reader.read_tag_list().unwrap(), [Tag::ShowFrame]);
         }
     }
+
+    /// Ensure that we return an error on invalid data.
+    #[test]
+    fn read_invalid_tag() {
+        let tag_bytes = [0xff, 0xff, 0xff, 0xff, 0xff, 0xff];
+        let mut reader = Reader::new(&tag_bytes[..], 5);
+        match reader.read_tag() {
+            Err(crate::error::Error::SwfParseError { .. }) => (),
+            result => {
+                panic!("Expected SwfParseError, got {:?}", result);
+            }
+        }
+    }
 }