diff --git a/README.adoc b/README.adoc
index a41992f..b785ac6 100644
--- a/README.adoc
+++ b/README.adoc
@@ -35,7 +35,12 @@ The value for `interval` can be set by using plain seconds or using units of `h`
 default to 60 seconds.
 
 ----
-# Update interval using value with units. Default value if not set is 60 sec.
+# Update interval using seconds as number.
+interval = 60
+
+# or ...
+
+# Update interval using value with units.
 interval = "2m 30s"
 ----
 
diff --git a/src/config.rs b/src/config.rs
index 0e7831b..5f8eb1b 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,11 +1,15 @@
-use regex::Regex;
-use serde::Deserialize;
+use std::fmt::Formatter;
 use std::time::Duration;
 use std::{env, fs};
 
+use regex::Regex;
+use serde::de::{Error, Visitor};
+use serde::{Deserialize, Deserializer};
+
 #[derive(Deserialize)]
 pub struct Config {
-    pub interval: Option<String>,
+    #[serde(default, deserialize_with = "deserialize_duration")]
+    pub interval: Option<Duration>,
     pub colors: Option<ColorConfig>,
     pub checks: Vec<CheckConfig>,
 }
@@ -60,15 +64,42 @@ pub fn get_config() -> Config {
     }
 }
 
-pub fn parse_duration(value: Option<String>) -> Duration {
-    let mut result = 0;
-    let value = match &value {
-        Some(value) => {
-            let result = value;
-            result.as_str()
+fn deserialize_duration<'de, D>(d: D) -> Result<Option<Duration>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    struct StringVisitor;
+
+    impl<'de> Visitor<'de> for StringVisitor {
+        type Value = String;
+
+        fn expecting(&self, f: &mut Formatter) -> std::fmt::Result {
+            f.write_str("a number or string with parsable duration")
         }
-        _ => return Duration::from_secs(60),
-    };
+
+        fn visit_i64<E>(self, v: i64) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            Ok(format!("{}", v))
+        }
+
+        fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            Ok(v.to_string())
+        }
+    }
+
+    match d.deserialize_string(StringVisitor) {
+        Ok(value) => Ok(parse_duration(value.as_str())),
+        Err(err) => Err(err),
+    }
+}
+
+fn parse_duration(value: &str) -> Option<Duration> {
+    let mut result = 0;
     if let Ok(re) =
         Regex::new(r"^((?P<hours>\d+)h\s*)?((?P<minutes>\d+)m\s*)?((?P<seconds>\d+)s?\s*)?$")
     {
@@ -93,59 +124,81 @@ pub fn parse_duration(value: Option<String>) -> Duration {
                 };
             }
         } else {
-            return Duration::from_secs(60);
+            return None;
         }
     }
-    Duration::from_secs(result)
+    Some(Duration::from_secs(result))
 }
 
 #[cfg(test)]
 mod tests {
-    use crate::config::parse_duration;
     use std::time::Duration;
 
+    use crate::config::{parse_duration, Config};
+
+    #[test]
+    fn test_should_parse_config_with_number_interval() {
+        let config: Config = toml::from_str(
+            r#"
+                interval = 123
+
+                [[checks]]
+                name = "example"
+                url = "https://example.com"
+            "#,
+        )
+        .unwrap();
+
+        assert_eq!(config.interval, Some(Duration::from_secs(123)));
+    }
+
+    #[test]
+    fn test_should_parse_config_with_parsed_interval() {
+        let config: Config = toml::from_str(
+            r#"
+                interval = "2m 3s"
+
+                [[checks]]
+                name = "example"
+                url = "https://example.com"
+            "#,
+        )
+        .unwrap();
+
+        assert_eq!(config.interval, Some(Duration::from_secs(123)));
+    }
+
+    #[test]
+    fn test_should_parse_config_without_interval() {
+        let config: Config = toml::from_str(
+            r#"
+                [[checks]]
+                name = "example"
+                url = "https://example.com"
+            "#,
+        )
+        .unwrap();
+
+        assert_eq!(config.interval, None);
+    }
+
     #[test]
     fn test_should_parse_durations() {
-        assert_eq!(
-            parse_duration(Some("1m30s".to_string())),
-            Duration::from_secs(90)
-        );
-        assert_eq!(
-            parse_duration(Some("2m".to_string())),
-            Duration::from_secs(120)
-        );
-        assert_eq!(
-            parse_duration(Some("1h1m1s".to_string())),
-            Duration::from_secs(3661)
-        );
-        assert_eq!(
-            parse_duration(Some("90".to_string())),
-            Duration::from_secs(90)
-        );
+        assert_eq!(parse_duration("1m30s"), Some(Duration::from_secs(90)));
+        assert_eq!(parse_duration("2m"), Some(Duration::from_secs(120)));
+        assert_eq!(parse_duration("1h1m1s"), Some(Duration::from_secs(3661)));
+        assert_eq!(parse_duration("90"), Some(Duration::from_secs(90)));
     }
 
     #[test]
     fn test_should_parse_durations_with_whitespaces() {
-        assert_eq!(
-            parse_duration(Some("1m 30s".to_string())),
-            Duration::from_secs(90)
-        );
-        assert_eq!(
-            parse_duration(Some("1h 1m 1s".to_string())),
-            Duration::from_secs(3661)
-        );
+        assert_eq!(parse_duration("1m 30s"), Some(Duration::from_secs(90)));
+        assert_eq!(parse_duration("1h 1m 1s"), Some(Duration::from_secs(3661)));
     }
 
     #[test]
     fn test_should_return_default_for_unparseable_durations() {
-        assert_eq!(parse_duration(None), Duration::from_secs(60));
-        assert_eq!(
-            parse_duration(Some("invalid".to_string())),
-            Duration::from_secs(60)
-        );
-        assert_eq!(
-            parse_duration(Some("1x30m10q".to_string())),
-            Duration::from_secs(60)
-        );
+        assert_eq!(parse_duration("invalid"), None);
+        assert_eq!(parse_duration("1x30m10q"), None);
     }
 }
diff --git a/src/main.rs b/src/main.rs
index 180c70f..16757e3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,14 +1,15 @@
-mod checker;
-mod config;
-
 use std::process;
+use std::time::Duration;
 
 use serde::Deserialize;
 use serde_json::json;
 use tokio::task;
 
 use crate::checker::{ActuatorChecker, CheckResult, HttpChecker, TcpChecker};
-use crate::config::{get_config, parse_duration, CheckConfig, CheckType};
+use crate::config::{get_config, CheckConfig, CheckType};
+
+mod checker;
+mod config;
 
 #[derive(Deserialize)]
 struct ClickEvent {
@@ -101,7 +102,11 @@ async fn main() {
         loop {
             let config = get_config();
             print_states(&config.checks).await;
-            std::thread::sleep(parse_duration(config.interval));
+            let interval = match config.interval {
+                Some(value) => value,
+                _ => Duration::from_secs(60),
+            };
+            std::thread::sleep(interval);
         }
     });