diff --git a/dune-project b/dune-project
index 24c1d0d..d6e8712 100644
--- a/dune-project
+++ b/dune-project
@@ -21,6 +21,7 @@
   (synopsis "In-memory resources for Eio")
   (description "Eio_mem provides in-memory resources for Eio")
   (depends
+    astring
     (eio (>= 1.4))
     (eio_main :with-test)
     (mdx :with-test)))
diff --git a/eio_mem.opam b/eio_mem.opam
index 5b1fd4e..480d32e 100644
--- a/eio_mem.opam
+++ b/eio_mem.opam
@@ -9,6 +9,7 @@ doc: "https://patrick.sirref.org/software/bib/docs/"
 bug-reports: "https://tangled.org/patrick.sirref.org/eio_mem/issues"
 depends: [
   "dune" {>= "3.21"}
+  "astring"
   "eio" {>= "1.4"}
   "eio_main" {with-test}
   "mdx" {with-test}
diff --git a/src/dune b/src/dune
index a984522..ae3a62b 100644
--- a/src/dune
+++ b/src/dune
@@ -1,4 +1,4 @@
 (library
  (name eio_mem)
  (public_name eio_mem)
- (libraries eio eio.unix fpath))
+ (libraries eio eio.unix astring))