diff --git a/src/config.rs b/src/config.rs
index 5786071..144566c 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -103,7 +103,14 @@ impl Settings {
         
         // Add environment variables
         debug!("CONFIG: Adding environment variables");
-        config_builder = config_builder.add_source(config::Environment::with_prefix("KEEP").separator("__"));
+        let mut env_source = config::Environment::with_prefix("KEEP").separator("__");
+        // Ignore empty KEEP_LIST_FORMAT
+        if let Ok(list_format) = std::env::var("KEEP_LIST_FORMAT") {
+            if list_format.is_empty() {
+                env_source = env_source.ignore_empty(true);
+            }
+        }
+        config_builder = config_builder.add_source(env_source);
         
         // Override with CLI args
         if let Some(dir) = &args.options.dir {