diff --git a/src/tests/mod.rs b/src/tests/mod.rs
index 21f7360ad..72932abbf 100644
--- a/src/tests/mod.rs
+++ b/src/tests/mod.rs
@@ -65,6 +65,9 @@ pub mod prelude {
     pub fn test_init() -> impl ScopeGuarding<Target = ()> {
         static DONE: OnceCell<()> = OnceCell::new();
         DONE.get_or_init(|| {
+            // If we are building with `cargo build` and have build w/ `cmake`, FISH_BUILD_DIR might
+            // not yet exist.
+            std::fs::create_dir_all(env!("FISH_BUILD_DIR")).unwrap();
             set_current_dir(env!("FISH_BUILD_DIR")).unwrap();
             {
                 let s = CString::new("").unwrap();