diff --git a/src/obj/str.rs b/src/obj/str.rs
index d9ef33a..359944d 100644
--- a/src/obj/str.rs
+++ b/src/obj/str.rs
@@ -24,6 +24,7 @@ impl Str {
                 attrs: Default::default(),
             },
             vtable: |obj_ref: ObjRef| vtable! {
+                BOOL_MEMBER_NAME.sym => Method::new_obj(obj_ref.clone(), STR_BOOL_METH.clone()),
                 STR_MEMBER_NAME.sym => Method::new_obj(obj_ref.clone(), STR_STR_METH.clone()),
                 REPR_MEMBER_NAME.sym => Method::new_obj(obj_ref.clone(), STR_REPR_METH.clone()),
                 INT_MEMBER_NAME.sym => Method::new_obj(obj_ref.clone(), STR_INT_METH.clone()),
@@ -48,6 +49,18 @@ impl Debug for Str {
 // Builtin Str functions
 ////////////////////////////////////////////////////////////////////////////////
 
+/// Str.__bool__(self) impl
+static STR_BOOL_METH: Lazy<NativeFunRef> = Lazy::new(|| {
+    NativeFun::new_obj(1, |_callee, vm, args| {
+        read_obj_downcast!(let str_obj: Option<&Str> = &args[0]);
+        let str_obj = str_obj.ok_or_else(|| Error::ValueError {
+            error: "expected Str value".to_string(),
+        })?;
+        vm.push(BoolRef::from(!str_obj.value.is_empty()));
+        Ok(crate::vm::signal::Signal::Return)
+    })
+});
+
 /// Str.__str__(self) impl
 static STR_STR_METH: Lazy<NativeFunRef> = Lazy::new(|| {
     NativeFun::new_obj(1, |_callee, vm, args| {