diff --git a/crates/lune-std/src/unsafe_library.rs b/crates/lune-std/src/unsafe_library.rs
index 3c0cbf4..3166050 100644
--- a/crates/lune-std/src/unsafe_library.rs
+++ b/crates/lune-std/src/unsafe_library.rs
@@ -18,5 +18,9 @@ pub fn set_unsafe_library_enabled(lua: &Lua, enabled: bool) {
 */
 #[must_use]
 pub fn get_unsafe_library_enabled(lua: &Lua) -> bool {
-    lua.app_data_ref::<UnsafeLibrary>().unwrap().0
+    if let Some(app_data) = lua.app_data_ref::<UnsafeLibrary>() {
+        app_data.0
+    } else {
+        false
+    }
 }
diff --git a/crates/lune/src/cli/repl.rs b/crates/lune/src/cli/repl.rs
index 78a6bd7..faeff73 100644
--- a/crates/lune/src/cli/repl.rs
+++ b/crates/lune/src/cli/repl.rs
@@ -17,7 +17,11 @@ enum PromptState {
 
 /// Launch an interactive REPL (default)
 #[derive(Debug, Clone, Default, Parser)]
-pub struct ReplCommand {}
+pub struct ReplCommand {
+    /// Allow unsafe libraries
+    #[clap(long, action)]
+    r#unsafe: bool,
+}
 
 impl ReplCommand {
     pub async fn run(self) -> Result<ExitCode> {
@@ -38,7 +42,7 @@ impl ReplCommand {
         let mut prompt_state = PromptState::Regular;
         let mut source_code = String::new();
 
-        let mut lune_instance = Runtime::new();
+        let mut lune_instance = Runtime::new().set_unsafe_library_enabled(self.r#unsafe);
 
         loop {
             let prompt = match prompt_state {