diff --git a/tokenizers/src/pre_tokenizers/mod.rs b/tokenizers/src/pre_tokenizers/mod.rs
index cf64fb876..c12646102 100644
--- a/tokenizers/src/pre_tokenizers/mod.rs
+++ b/tokenizers/src/pre_tokenizers/mod.rs
@@ -144,4 +144,43 @@ mod tests {
             PreTokenizerWrapper::WhitespaceSplit(WhitespaceSplit {})
         );
     }
+
+    #[test]
+    fn pre_tokenizer_deserialization_no_type() {
+        let json = r#"{"replacement":"▁","add_prefix_space":true, "prepend_scheme":"always"}}"#;
+        let reconstructed = serde_json::from_str::<PreTokenizerWrapper>(json);
+        match reconstructed {
+            Err(err) => assert_eq!(
+                err.to_string(),
+                "data did not match any variant of untagged enum PreTokenizerWrapper"
+            ),
+            _ => panic!("Expected an error here"),
+        }
+
+        let json = r#"{"type":"Metaspace", "replacement":"▁" }"#;
+        let reconstructed = serde_json::from_str::<PreTokenizerWrapper>(json);
+        assert_eq!(
+            reconstructed.unwrap(),
+            PreTokenizerWrapper::Metaspace(Metaspace::default())
+        );
+
+        let json = r#"{"type":"Metaspace", "add_prefix_space":true }"#;
+        let reconstructed = serde_json::from_str::<PreTokenizerWrapper>(json);
+        match reconstructed {
+            Err(err) => assert_eq!(
+                err.to_string(),
+                "data did not match any variant of untagged enum PreTokenizerWrapper"
+            ),
+            _ => panic!("Expected an error here"),
+        }
+        let json = r#"{"behavior":"default_split"}"#;
+        let reconstructed = serde_json::from_str::<PreTokenizerWrapper>(json);
+        match reconstructed {
+            Err(err) => assert_eq!(
+                err.to_string(),
+                "data did not match any variant of untagged enum PreTokenizerWrapper"
+            ),
+            _ => panic!("Expected an error here"),
+        }
+    }
 }
diff --git a/tokenizers/src/processors/mod.rs b/tokenizers/src/processors/mod.rs
index 130a537ba..869cc6891 100644
--- a/tokenizers/src/processors/mod.rs
+++ b/tokenizers/src/processors/mod.rs
@@ -87,4 +87,42 @@ mod tests {
             PostProcessorWrapper::Bert(bert)
         );
     }
+
+    #[test]
+    fn post_processor_deserialization_no_type() {
+        let json = r#"{"add_prefix_space": true, "trim_offsets": false, "use_regex": false}"#;
+        let reconstructed = serde_json::from_str::<PostProcessorWrapper>(json);
+        match reconstructed {
+            Err(err) => assert_eq!(
+                err.to_string(),
+                "data did not match any variant of untagged enum PostProcessorWrapper"
+            ),
+            _ => panic!("Expected an error here"),
+        }
+
+        let json = r#"{"sep":["[SEP]",102],"cls":["[CLS]",101]}"#;
+        let reconstructed = serde_json::from_str::<PostProcessorWrapper>(json);
+        assert!(matches!(
+            reconstructed.unwrap(),
+            PostProcessorWrapper::Bert(_)
+        ));
+
+        let json =
+            r#"{"sep":["</s>",2], "cls":["<s>",0], "trim_offsets":true, "add_prefix_space":true}"#;
+        let reconstructed = serde_json::from_str::<PostProcessorWrapper>(json);
+        assert!(matches!(
+            reconstructed.unwrap(),
+            PostProcessorWrapper::Roberta(_)
+        ));
+
+        let json = r#"{"type":"RobertaProcessing", "sep":["</s>",2] }"#;
+        let reconstructed = serde_json::from_str::<PostProcessorWrapper>(json);
+        match reconstructed {
+            Err(err) => assert_eq!(
+                err.to_string(),
+                "data did not match any variant of untagged enum PostProcessorWrapper"
+            ),
+            _ => panic!("Expected an error here"),
+        }
+    }
 }