diff --git a/tests/deser_test b/tests/deser_test
index 7d8c7dc..773ad0b 100644
--- a/tests/deser_test
+++ b/tests/deser_test
@@ -67,93 +67,96 @@ fn cbor_bytes_sz(bytes: Vec<u8>, sz: cbor_event::StringLenSz) -> Vec<u8> {
     buf.finalize()
 }
 
-fn print_cbor_types(obj_name: &str, vec: Vec<u8>) {
-    use cbor_event::Type;
-    let mut raw = cbor_event::de::Deserializer::from(vec);
-    let mut lens = Vec::new();
-    let consume_elem = |lens: &mut Vec<cbor_event::LenSz>| {
-        if let Some(len) = lens.last_mut() {
-            if let cbor_event::LenSz::Len(n, _) = len {
-                *n -= 1;
+#[cfg(test)]
+mod tests {
+    fn print_cbor_types(obj_name: &str, vec: Vec<u8>) {
+        use cbor_event::Type;
+        let mut raw = cbor_event::de::Deserializer::from(vec);
+        let mut lens = Vec::new();
+        let consume_elem = |lens: &mut Vec<cbor_event::LenSz>| {
+            if let Some(len) = lens.last_mut() {
+                if let cbor_event::LenSz::Len(n, _) = len {
+                    *n -= 1;
+                }
             }
-        }
-    };
-    let reduce_depth = |lens: &mut Vec<cbor_event::LenSz>| {
-        while let Some(cbor_event::LenSz::Len(0, _)) = lens.last() {
-            lens.pop();
-            println!("{}}}", "\t".repeat(lens.len()));
-        }
-    };
-    println!("{} = {{", obj_name);
-    loop {
-        print!("{}", "\t".repeat(lens.len()));
-        match raw.cbor_type() {
-            Err(_) => break,
-            Ok(Type::UnsignedInteger) => {
-                let (x, sz) = raw.unsigned_integer_sz().unwrap();
-                println!("UINT({}, {:?})", x, sz);
-                consume_elem(&mut lens);
-                reduce_depth(&mut lens);
-            },
-            Ok(Type::NegativeInteger) => {
-                let (x, sz) = raw.negative_integer_sz().unwrap();
-                println!("NINT({}, {:?})", x, sz);
-                consume_elem(&mut lens);
-                reduce_depth(&mut lens);
-            },
-            Ok(Type::Bytes) => {
-                let (x, sz) = raw.bytes_sz().unwrap();
-                println!("BYTES({:?}, {:?})", x, sz);
-                consume_elem(&mut lens);
-                reduce_depth(&mut lens);
-            },
-            Ok(Type::Text) => {
-                let (x, sz) = raw.text_sz().unwrap();
-                println!("TEXT(\"{}\", {:?})", x, sz);
-                consume_elem(&mut lens);
-                reduce_depth(&mut lens);
-            },
-            Ok(Type::Array) => {
-                let len = raw.array_sz().unwrap();
-                println!("ARRAY({:?}) {{", len);
-                consume_elem(&mut lens);
-                lens.push(len);
-                if let cbor_event::LenSz::Len(0, _sz) = len {
+        };
+        let reduce_depth = |lens: &mut Vec<cbor_event::LenSz>| {
+            while let Some(cbor_event::LenSz::Len(0, _)) = lens.last() {
+                lens.pop();
+                println!("{}}}", "\t".repeat(lens.len()));
+            }
+        };
+        println!("{} = {{", obj_name);
+        loop {
+            print!("{}", "\t".repeat(lens.len()));
+            match raw.cbor_type() {
+                Err(_) => break,
+                Ok(Type::UnsignedInteger) => {
+                    let (x, sz) = raw.unsigned_integer_sz().unwrap();
+                    println!("UINT({}, {:?})", x, sz);
+                    consume_elem(&mut lens);
                     reduce_depth(&mut lens);
-                }
-            },
-            Ok(Type::Map) => {
-                let len = raw.map_sz().unwrap();
-                println!("MAP({:?}) {{", len);
-                consume_elem(&mut lens);
-                lens.push(match len {
-                    cbor_event::LenSz::Len(n, sz) => cbor_event::LenSz::Len(2 * n, sz),
-                    cbor_event::LenSz::Indefinite => cbor_event::LenSz::Indefinite,
-                });
-                if let cbor_event::LenSz::Len(0, _sz) = len {
+                },
+                Ok(Type::NegativeInteger) => {
+                    let (x, sz) = raw.negative_integer_sz().unwrap();
+                    println!("NINT({}, {:?})", x, sz);
+                    consume_elem(&mut lens);
                     reduce_depth(&mut lens);
-                }
-            },
-            Ok(Type::Tag) => {
-                let (tag, sz) = raw.tag_sz().unwrap();
-                println!("TAG({}, {:?})", tag, sz);
-            },
-            Ok(Type::Special) => {
-                let special = raw.special().unwrap();
-                println!("SPECIAL({:?})", special);
-                if special == cbor_event::Special::Break {
-                    if let Some(cbor_event::LenSz::Indefinite) = lens.last() {
-                        lens.pop();
+                },
+                Ok(Type::Bytes) => {
+                    let (x, sz) = raw.bytes_sz().unwrap();
+                    println!("BYTES({:?}, {:?})", x, sz);
+                    consume_elem(&mut lens);
+                    reduce_depth(&mut lens);
+                },
+                Ok(Type::Text) => {
+                    let (x, sz) = raw.text_sz().unwrap();
+                    println!("TEXT(\"{}\", {:?})", x, sz);
+                    consume_elem(&mut lens);
+                    reduce_depth(&mut lens);
+                },
+                Ok(Type::Array) => {
+                    let len = raw.array_sz().unwrap();
+                    println!("ARRAY({:?}) {{", len);
+                    consume_elem(&mut lens);
+                    lens.push(len);
+                    if let cbor_event::LenSz::Len(0, _sz) = len {
                         reduce_depth(&mut lens);
-                    } else {
-                        panic!("unexpected break");
                     }
-                } else {
+                },
+                Ok(Type::Map) => {
+                    let len = raw.map_sz().unwrap();
+                    println!("MAP({:?}) {{", len);
                     consume_elem(&mut lens);
-                    reduce_depth(&mut lens);
-                }
-            },
+                    lens.push(match len {
+                        cbor_event::LenSz::Len(n, sz) => cbor_event::LenSz::Len(2 * n, sz),
+                        cbor_event::LenSz::Indefinite => cbor_event::LenSz::Indefinite,
+                    });
+                    if let cbor_event::LenSz::Len(0, _sz) = len {
+                        reduce_depth(&mut lens);
+                    }
+                },
+                Ok(Type::Tag) => {
+                    let (tag, sz) = raw.tag_sz().unwrap();
+                    println!("TAG({}, {:?})", tag, sz);
+                },
+                Ok(Type::Special) => {
+                    let special = raw.special().unwrap();
+                    println!("SPECIAL({:?})", special);
+                    if special == cbor_event::Special::Break {
+                        if let Some(cbor_event::LenSz::Indefinite) = lens.last() {
+                            lens.pop();
+                            reduce_depth(&mut lens);
+                        } else {
+                            panic!("unexpected break");
+                        }
+                    } else {
+                        consume_elem(&mut lens);
+                        reduce_depth(&mut lens);
+                    }
+                },
+            }
         }
+        println!("}}");
     }
-    println!("}}");
 }