diff --git a/Cargo.toml b/Cargo.toml
index 45c88d7..966b932 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,7 +19,7 @@ is-it-maintained-open-issues = { repository = "async-email/async-smtp" }
 
 [dependencies]
 log = "^0.4"
-nom = { version = "^5.0", optional = true }
+nom = { version = "^7.0", optional = true }
 bufstream = { version = "^0.1", optional = true }
 base64 = { version = "^0.13", optional = true }
 hostname = { version = "0.3.1", optional = true }
diff --git a/src/smtp/client/inner.rs b/src/smtp/client/inner.rs
index 20c8b81..8debc55 100644
--- a/src/smtp/client/inner.rs
+++ b/src/smtp/client/inner.rs
@@ -282,11 +282,11 @@ impl<S: Connector + Write + Read + Unpin> InnerClient<S> {
                     return Err(response.into());
                 }
                 Err(nom::Err::Failure(e)) => {
-                    return Err(Error::Parsing(e.1));
+                    return Err(Error::Parsing(e.code));
                 }
                 Err(nom::Err::Incomplete(_)) => { /* read more */ }
                 Err(nom::Err::Error(e)) => {
-                    return Err(Error::Parsing(e.1));
+                    return Err(Error::Parsing(e.code));
                 }
             }
         }
diff --git a/src/smtp/commands.rs b/src/smtp/commands.rs
index 5a0fdb1..f5eefaa 100644
--- a/src/smtp/commands.rs
+++ b/src/smtp/commands.rs
@@ -11,7 +11,7 @@ use std::convert::AsRef;
 use std::fmt::{self, Display, Formatter};
 
 /// EHLO command
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Eq, Clone, Debug)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -34,7 +34,7 @@ impl EhloCommand {
 }
 
 /// STARTTLS command
-#[derive(PartialEq, Clone, Debug, Copy)]
+#[derive(PartialEq, Eq, Clone, Debug, Copy)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -48,7 +48,7 @@ impl Display for StarttlsCommand {
 }
 
 /// MAIL command
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Eq, Clone, Debug)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -80,7 +80,7 @@ impl MailCommand {
 }
 
 /// RCPT command
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Eq, Clone, Debug)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -111,7 +111,7 @@ impl RcptCommand {
 }
 
 /// DATA command
-#[derive(PartialEq, Clone, Debug, Copy)]
+#[derive(PartialEq, Eq, Clone, Debug, Copy)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -125,7 +125,7 @@ impl Display for DataCommand {
 }
 
 /// QUIT command
-#[derive(PartialEq, Clone, Debug, Copy)]
+#[derive(PartialEq, Eq, Clone, Debug, Copy)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -139,7 +139,7 @@ impl Display for QuitCommand {
 }
 
 /// NOOP command
-#[derive(PartialEq, Clone, Debug, Copy)]
+#[derive(PartialEq, Eq, Clone, Debug, Copy)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -153,7 +153,7 @@ impl Display for NoopCommand {
 }
 
 /// HELP command
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Eq, Clone, Debug)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -180,7 +180,7 @@ impl HelpCommand {
 }
 
 /// VRFY command
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Eq, Clone, Debug)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -203,7 +203,7 @@ impl VrfyCommand {
 }
 
 /// EXPN command
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Eq, Clone, Debug)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -226,7 +226,7 @@ impl ExpnCommand {
 }
 
 /// RSET command
-#[derive(PartialEq, Clone, Debug, Copy)]
+#[derive(PartialEq, Eq, Clone, Debug, Copy)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
@@ -240,7 +240,7 @@ impl Display for RsetCommand {
 }
 
 /// AUTH command
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Eq, Clone, Debug)]
 #[cfg_attr(
     feature = "serde-impls",
     derive(serde_derive::Serialize, serde_derive::Deserialize)
diff --git a/src/smtp/error.rs b/src/smtp/error.rs
index 665d020..ee618bb 100644
--- a/src/smtp/error.rs
+++ b/src/smtp/error.rs
@@ -62,12 +62,12 @@ pub enum Error {
     Socks5Error(#[from] fast_socks5::SocksError),
 }
 
-impl From<nom::Err<(&str, nom::error::ErrorKind)>> for Error {
-    fn from(err: nom::Err<(&str, nom::error::ErrorKind)>) -> Error {
+impl From<nom::Err<nom::error::Error<&str>>> for Error {
+    fn from(err: nom::Err<nom::error::Error<&str>>) -> Error {
         Parsing(match err {
             nom::Err::Incomplete(_) => nom::error::ErrorKind::Complete,
-            nom::Err::Failure((_, k)) => k,
-            nom::Err::Error((_, k)) => k,
+            nom::Err::Failure(e) => e.code,
+            nom::Err::Error(e) => e.code,
         })
     }
 }
diff --git a/src/smtp/extension.rs b/src/smtp/extension.rs
index 51a80c7..c4f18be 100644
--- a/src/smtp/extension.rs
+++ b/src/smtp/extension.rs
@@ -156,7 +156,7 @@ impl ServerInfo {
             }
 
             let split: Vec<&str> = line.split_whitespace().collect();
-            match split.get(0).copied() {
+            match split.first().copied() {
                 Some("8BITMIME") => {
                     features.insert(Extension::EightBitMime);
                 }
diff --git a/src/smtp/response.rs b/src/smtp/response.rs
index 1cd4e4d..4989f40 100644
--- a/src/smtp/response.rs
+++ b/src/smtp/response.rs
@@ -253,7 +253,10 @@ pub(crate) fn parse_response(i: &str) -> IResult<&str, Response> {
 
     // Check that all codes are equal.
     if !lines.iter().all(|&(ref code, _, _)| *code == last_code) {
-        return Err(nom::Err::Failure(("", nom::error::ErrorKind::Not)));
+        return Err(nom::Err::Failure(nom::error::Error::new(
+            "",
+            nom::error::ErrorKind::Not,
+        )));
     }
 
     // Extract text from lines, and append last line.
diff --git a/src/smtp/smtp_client.rs b/src/smtp/smtp_client.rs
index 0568bad..4513bb6 100644
--- a/src/smtp/smtp_client.rs
+++ b/src/smtp/smtp_client.rs
@@ -72,7 +72,7 @@ impl Display for ServerAddress {
 
 /// Struct holding the configuration for a socks5 proxy connection
 #[cfg(feature = "socks5")]
-#[derive(Default, Clone, Debug, PartialEq)]
+#[derive(Default, Clone, Debug, Eq, PartialEq)]
 pub struct Socks5Config {
     /// Hostname of the socks5 server
     pub host: String,