diff --git a/z3/src/ast.rs b/z3/src/ast.rs
index eab3a4e9..c2fdc3ad 100644
--- a/z3/src/ast.rs
+++ b/z3/src/ast.rs
@@ -1177,6 +1177,11 @@ impl<'ctx> String<'ctx> {
         concat(Z3_mk_seq_concat, String<'ctx>);
     }
 
+    unop! {
+        /// Gets the length of `Self`.
+        length(Z3_mk_seq_length, Int<'ctx>);
+    }
+
     binop! {
         /// Checks whether `Self` contains a substring
         contains(Z3_mk_seq_contains, Bool<'ctx>);