diff --git a/src/quirks.rs b/src/quirks.rs
index 1ca4a98..070f2fb 100644
--- a/src/quirks.rs
+++ b/src/quirks.rs
@@ -75,8 +75,10 @@ pub fn get_package_quirks<'a>(
 /// # Returns
 /// * `Vec<String>` - List of extra dependencies, or empty vector if none
 pub fn get_deb_extra_dependencies(package: &str) -> Vec<String> {
-    if let Some(quirks) = &get_package_quirks(&QUIRKS_DATA, package).unwrap().deb {
-        return quirks.extra_dependencies.clone();
+    if let Some(quirks) = get_package_quirks(&QUIRKS_DATA, package)
+        && let Some(deb_quirks) = &quirks.deb
+    {
+        return deb_quirks.extra_dependencies.clone();
     }
 
     Vec::new()
@@ -109,3 +111,16 @@ pub fn get_package_directories(package: &str) -> Vec<String> {
 
     Vec::new()
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_unknown_package_has_no_quirks() {
+        // A package absent from quirks.yml (currently every package) has no
+        // extra dependencies nor custom directories, and must not panic
+        assert!(get_deb_extra_dependencies("not-in-quirks").is_empty());
+        assert!(get_package_directories("not-in-quirks").is_empty());
+    }
+}