diff --git a/swift/Sources/FlatBuffers/Mutable.swift b/swift/Sources/FlatBuffers/Mutable.swift
index f77945c..9763c3f 100644
--- a/swift/Sources/FlatBuffers/Mutable.swift
+++ b/swift/Sources/FlatBuffers/Mutable.swift
@@ -14,7 +14,11 @@
  * limitations under the License.
  */
 
+#if !os(WASI)
 import Foundation
+#else
+import SwiftOverlayShims
+#endif
 
 /// Mutable is a protocol that allows us to mutate Scalar values within a ``ByteBuffer``
 public protocol Mutable {