diff --git a/src/validate.rs b/src/validate.rs
index 6964cb35c..a6b5c7c52 100644
--- a/src/validate.rs
+++ b/src/validate.rs
@@ -322,12 +322,14 @@ fn validate_duplicate_team_entries(data: &Data, errors: &mut Vec<String>) {
             errors.push(e.to_string());
         }
 
+        let alumni = || {
+            team.explicit_alumni()
+                .iter()
+                .map(|alum| alum.github.as_str())
+        };
+
         // Check alumni for duplicates
-        if let Err(e) = check_duplicates(
-            team.name(),
-            "alumni",
-            team.explicit_alumni().iter().map(|a| a.github.as_str()),
-        ) {
+        if let Err(e) = check_duplicates(team.name(), "alumni", alumni()) {
             errors.push(e.to_string());
         }
 
@@ -335,10 +337,7 @@ fn validate_duplicate_team_entries(data: &Data, errors: &mut Vec<String>) {
         if let Err(e) = check_duplicates(
             team.name(),
             "leads + alumni",
-            team.explicit_alumni()
-                .iter()
-                .map(|a| a.github.as_str())
-                .chain(team.explicit_leads().iter().map(|s| s.as_str())),
+            alumni().chain(team.explicit_leads().iter().map(|s| s.as_str())),
         ) {
             errors.push(e.to_string());
         }
@@ -347,10 +346,7 @@ fn validate_duplicate_team_entries(data: &Data, errors: &mut Vec<String>) {
         if let Err(e) = check_duplicates(
             team.name(),
             "members + alumni",
-            team.explicit_alumni()
-                .iter()
-                .map(|a| a.github.as_str())
-                .chain(team.explicit_members().iter().map(|s| s.github.as_str())),
+            alumni().chain(team.explicit_members().iter().map(|s| s.github.as_str())),
         ) {
             errors.push(e.to_string());
         }