diff --git a/src/cli/configuration/mod.rs b/src/cli/configuration/mod.rs
index 6d95e3a..08f79fa 100644
--- a/src/cli/configuration/mod.rs
+++ b/src/cli/configuration/mod.rs
@@ -249,7 +249,6 @@ mod tests {
             r#"
             library:
               github:
-                instance: https://api.github.com/
                 owner: jdno
                 repository: flowcrafter
             workflows:
diff --git a/src/github/configuration.rs b/src/github/configuration.rs
index b9ce937..148dccb 100644
--- a/src/github/configuration.rs
+++ b/src/github/configuration.rs
@@ -10,6 +10,7 @@ use crate::github::repository::Repository;
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct GitHubConfiguration {
     #[cfg_attr(feature = "serde", serde(default = "default_instance"))]
+    #[cfg_attr(feature = "serde", serde(skip_serializing_if = "is_default_instance"))]
     #[builder(default = default_instance())]
     instance: Url,
 
@@ -44,6 +45,10 @@ fn default_instance() -> Url {
     Url::parse("https://api.github.com").expect("failed to parse hard-coded GitHub URL 🤯")
 }
 
+fn is_default_instance(instance: &Url) -> bool {
+    instance == &default_instance()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -101,6 +106,44 @@ mod tests {
         assert_send::<GitHubConfiguration>();
     }
 
+    #[cfg(feature = "serde")]
+    #[test]
+    fn trait_serialize_with_default_instance() {
+        let configuration = GitHubConfiguration::builder()
+            .owner("jdno")
+            .repository("flowcrafter")
+            .build();
+
+        let yaml = indoc!(
+            r#"
+            owner: jdno
+            repository: flowcrafter
+            "#
+        );
+
+        assert_eq!(yaml, serde_yaml::to_string(&configuration).unwrap());
+    }
+
+    #[cfg(feature = "serde")]
+    #[test]
+    fn trait_serialize_with_custom_instance() {
+        let configuration = GitHubConfiguration::builder()
+            .instance(Url::parse("https://github.example.com").unwrap())
+            .owner("jdno")
+            .repository("flowcrafter")
+            .build();
+
+        let yaml = indoc!(
+            r#"
+            instance: https://github.example.com/
+            owner: jdno
+            repository: flowcrafter
+            "#
+        );
+
+        assert_eq!(yaml, serde_yaml::to_string(&configuration).unwrap());
+    }
+
     #[test]
     fn trait_sync() {
         fn assert_sync<T: Sync>() {}