diff --git a/Cargo.toml b/Cargo.toml
index 524422c..5deabea 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -25,8 +25,8 @@ is-it-maintained-open-issues = { repository = "jonhoo/rust-imap" }
 native-tls = "0.2.2"
 regex = "1.0"
 bufstream = "0.1"
-imap-proto = "0.8"
-nom = "4.0"
+imap-proto = "0.9.0"
+nom = "5.0"
 base64 = "0.10"
 chrono = "0.4"
 lazy_static = "1.4"
diff --git a/src/parse.rs b/src/parse.rs
index dbcb27f..7c79b59 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -351,6 +351,21 @@ mod tests {
         }
     }
 
+    #[test]
+    fn parse_capability_case_insensitive_test() {
+        // Test that "IMAP4REV1" (instead of "IMAP4rev1") is accepted
+        let expected_capabilities = vec!["IMAP4rev1", "STARTTLS"];
+        let lines = b"* CAPABILITY IMAP4REV1 STARTTLS\r\n";
+        let (mut send, recv) = mpsc::channel();
+        let capabilities = parse_capabilities(lines.to_vec(), &mut send).unwrap();
+        // shouldn't be any unexpected responses parsed
+        assert!(recv.try_recv().is_err());
+        assert_eq!(capabilities.len(), 2);
+        for e in expected_capabilities {
+            assert!(capabilities.has_str(e));
+        }
+    }
+
     #[test]
     #[should_panic]
     fn parse_capability_invalid_test() {