diff --git a/Cargo.lock b/Cargo.lock
index f0026c5a35..8ba859643b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -207,12 +207,12 @@ checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
 
 [[package]]
 name = "cap-fs-ext"
-version = "0.7.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "724c2735539ad3ab51f04a0d84bca8c23398e558e810254a6996867fd6c7db81"
+checksum = "eac51b267ca1f2abe043f6193ff8ef119cdcfd46f10a1644c76d41daf55a5b73"
 dependencies = [
- "cap-primitives",
- "cap-std",
+ "cap-primitives 0.8.0",
+ "cap-std 0.8.0",
 ]
 
 [[package]]
@@ -226,7 +226,23 @@ dependencies = [
  "ipnet",
  "libc",
  "once_cell",
- "posish 0.5.2",
+ "posish",
+ "winapi",
+ "winx 0.21.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "cap-primitives"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43639eaff5966a4904bf0441ad4b6a8169b463e58f0cb34140dc8555d387b699"
+dependencies = [
+ "errno",
+ "fs-set-times",
+ "ipnet",
+ "libc",
+ "once_cell",
+ "posish",
  "winapi",
  "winx 0.21.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -237,7 +253,16 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0760daa4e6270daa9c5c6ad133108fb77edfe023a019c392d98dd769defa42d5"
 dependencies = [
- "cap-primitives",
+ "cap-primitives 0.7.0",
+]
+
+[[package]]
+name = "cap-std"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9d28ff1a5e60755c62be712baf75794892eb63a8b5bc5c4a7911b3549333e96"
+dependencies = [
+ "cap-primitives 0.8.0",
 ]
 
 [[package]]
@@ -934,11 +959,11 @@ checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
 
 [[package]]
 name = "fs-set-times"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a37c11eb7933093dd2a56c9c4d934a754b56e672fb8c2b46d50997dd2b4392d"
+checksum = "08b6f6626f73621230f712be2ee1a9e70bf3d7f38ffbd75a80b8ed0d925d1df1"
 dependencies = [
- "posish 0.4.1",
+ "posish",
  "winapi",
 ]
 
@@ -1509,19 +1534,6 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c917123afa01924fc84bb20c4c03f004d9c38e5127e3c039bbf7f4b9c76a2f6b"
 
-[[package]]
-name = "posish"
-version = "0.4.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a81e5017f1c873447782cd776e6ec307af670ecad29e934042005a0dec6864dd"
-dependencies = [
- "bitflags",
- "cfg-if 1.0.0",
- "errno",
- "itoa",
- "libc",
-]
-
 [[package]]
 name = "posish"
 version = "0.5.2"
@@ -2076,7 +2088,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "95457b1e5a9657ffd02a43048aeb083f20848d82176c0e1313facc1a23ba74da"
 dependencies = [
  "atty",
- "posish 0.5.2",
+ "posish",
  "winapi",
  "winx 0.21.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2135,6 +2147,7 @@ name = "test-programs"
 version = "0.19.0"
 dependencies = [
  "anyhow",
+ "cap-std 0.8.0",
  "cfg-if 1.0.0",
  "os_pipe",
  "pretty_env_logger",
@@ -2378,7 +2391,7 @@ version = "0.21.0"
 dependencies = [
  "anyhow",
  "cap-fs-ext",
- "cap-std",
+ "cap-std 0.8.0",
  "cfg-if 1.0.0",
  "fs-set-times",
  "getrandom 0.2.0",
@@ -2394,7 +2407,7 @@ name = "wasi-c2-wasmtime"
 version = "0.21.0"
 dependencies = [
  "anyhow",
- "cap-std",
+ "cap-std 0.7.0",
  "wasi-c2",
  "wasmtime",
  "wasmtime-wiggle",
diff --git a/crates/test-programs/Cargo.toml b/crates/test-programs/Cargo.toml
index dce5b74e65..b1f8e6ac40 100644
--- a/crates/test-programs/Cargo.toml
+++ b/crates/test-programs/Cargo.toml
@@ -19,6 +19,7 @@ tempfile = "3.1.0"
 os_pipe = "0.9"
 anyhow = "1.0.19"
 wat = "1.0.23"
+cap-std = "0.8"
 
 [features]
 test_programs = []
diff --git a/crates/test-programs/build.rs b/crates/test-programs/build.rs
index 8260a77aee..d185be4ed3 100644
--- a/crates/test-programs/build.rs
+++ b/crates/test-programs/build.rs
@@ -144,7 +144,11 @@ mod wasi_tests {
         let workspace = if no_preopens(testsuite, stemstr) {
             "None"
         } else {
-            "Some(std::path::Path::new(&bin_name))"
+            writeln!(
+                out,
+                "        let workspace = utils::prepare_workspace(&bin_name)?;"
+            )?;
+            "Some(workspace.path())"
         };
         writeln!(
             out,
diff --git a/crates/test-programs/tests/wasm_tests/runtime.rs b/crates/test-programs/tests/wasm_tests/runtime.rs
index 9082517703..e5234dd640 100644
--- a/crates/test-programs/tests/wasm_tests/runtime.rs
+++ b/crates/test-programs/tests/wasm_tests/runtime.rs
@@ -14,22 +14,13 @@ pub fn instantiate(data: &[u8], bin_name: &str, workspace: Option<&Path>) -> any
 
     builder.arg(bin_name)?.arg(".")?.inherit_stdio();
 
-    /*
-        if let Some(workspace) = workspace {
-            match preopen_type {
-                PreopenType::OS => {
-                    let preopen_dir = wasi_common::preopen_dir(workspace)
-                        .context(format!("error while preopening {:?}", workspace))?;
-                    builder.preopened_dir(preopen_dir, ".");
-                }
-                PreopenType::Virtual => {
-                    // we can ignore the workspace path for virtual preopens because virtual preopens
-                    // don't exist in the filesystem anyway - no name conflict concerns.
-                    builder.preopened_virt(VirtualDirEntry::empty_directory(), ".");
-                }
-            }
-        }
-    */
+    if let Some(workspace) = workspace {
+        let dirfd =
+            File::open(workspace).context(format!("error while preopening {:?}", workspace))?;
+        let preopen_dir = unsafe { cap_std::fs::Dir::from_std_file(dirfd) };
+        builder.preopened_dir(Box::new(preopen_dir), ".")?;
+    }
+
     /*
         // The nonstandard thing we do with `WasiCtxBuilder` is to ensure that
         // `stdin` is always an unreadable pipe. This is expected in the test suite