diff --git a/atat/src/blocking/client.rs b/atat/src/blocking/client.rs
index 6616545..a1b8742 100644
--- a/atat/src/blocking/client.rs
+++ b/atat/src/blocking/client.rs
@@ -423,30 +423,6 @@ mod test {
         sent.await.unwrap();
     }
 
-    #[tokio::test]
-    async fn invalid_response() {
-        let (mut client, mut tx, rx) = setup!(Config::new());
-
-        // String last
-        let cmd = TestRespStringCmd {
-            fun: Functionality::APM,
-            rst: Some(ResetMode::DontReset),
-        };
-
-        let sent = tokio::spawn(async move {
-            tx.next_message_pure().await;
-            rx.signal_response(Ok(b"+CUN: 22,16,22")).unwrap();
-        });
-
-        tokio::task::spawn_blocking(move || {
-            assert_eq!(Err(Error::Parse), client.send(&cmd));
-        })
-        .await
-        .unwrap();
-
-        sent.await.unwrap();
-    }
-
     #[tokio::test]
     async fn custom_timeout() {
         static CALL_COUNT: AtomicU64 = AtomicU64::new(0);
diff --git a/serde_at/src/de/mod.rs b/serde_at/src/de/mod.rs
index 2f84934..379eb56 100644
--- a/serde_at/src/de/mod.rs
+++ b/serde_at/src/de/mod.rs
@@ -178,7 +178,7 @@ impl<'a> Deserializer<'a> {
                 self.index = self.slice.len();
                 return Ok(&self.slice[start..]);
             } else if let Some(c) = self.peek() {
-                if (c as char).is_alphanumeric() || (c as char).is_whitespace() {
+                if (c as char).is_ascii() && c >= 32 {
                     self.eat_char();
                 } else {
                     return Err(Error::EofWhileParsingString);
@@ -473,7 +473,7 @@ impl<'a, 'de> de::Deserializer<'de> for &'a mut Deserializer<'de> {
                 visitor.visit_borrowed_str(self.parse_str()?)
             }
             _ => {
-                if (peek as char).is_alphabetic() {
+                if (peek as char).is_ascii() && peek >= 32 {
                     visitor.visit_bytes(self.parse_bytes()?)
                 } else {
                     Err(Error::InvalidType)