diff --git a/wasi-common-cbindgen/Cargo.toml b/wasi-common-cbindgen/Cargo.toml
index 75bb538d46..527a7781e8 100644
--- a/wasi-common-cbindgen/Cargo.toml
+++ b/wasi-common-cbindgen/Cargo.toml
@@ -10,3 +10,6 @@ proc-macro = true
 [dependencies]
 syn = { version = "0.15.34", features = ["full"] }
 quote = "0.6.12"
+
+[dev-dependencies]
+trybuild = "1.0.4"
\ No newline at end of file
diff --git a/wasi-common-cbindgen/src/lib.rs b/wasi-common-cbindgen/src/lib.rs
index 65977ad2b9..41961166f5 100644
--- a/wasi-common-cbindgen/src/lib.rs
+++ b/wasi-common-cbindgen/src/lib.rs
@@ -10,6 +10,9 @@ pub fn wasi_common_cbindgen(attr: TokenStream, function: TokenStream) -> TokenSt
 
     let function = syn::parse_macro_input!(function as syn::ItemFn);
 
+    // capture visibility
+    let vis = &function.vis;
+
     // generate C fn name prefixed with __wasi_
     let fn_ident = &function.ident;
     let concatenated = format!("__wasi_{}", fn_ident);
@@ -54,7 +57,7 @@ pub fn wasi_common_cbindgen(attr: TokenStream, function: TokenStream) -> TokenSt
     let result = quote! {
         #function
 
-        pub unsafe extern "C" fn #c_fn_ident(
+        #vis unsafe extern "C" fn #c_fn_ident(
             #(
                 #arg_ident: #arg_type,
             )*
diff --git a/wasi-common-cbindgen/tests/mut_args.rs b/wasi-common-cbindgen/tests/mut_args.rs
new file mode 100644
index 0000000000..036f8d86cc
--- /dev/null
+++ b/wasi-common-cbindgen/tests/mut_args.rs
@@ -0,0 +1,20 @@
+extern crate wasi_common_cbindgen;
+
+pub use wasi_common_cbindgen::wasi_common_cbindgen;
+
+#[wasi_common_cbindgen]
+fn mut_args(a: &mut usize) {
+    *a = *a + 1
+}
+
+fn main() {
+    let mut expected = Box::new(2);
+    mut_args(expected.as_mut());
+    let given = unsafe {
+        let given = Box::new(2);
+        let raw = Box::into_raw(given);
+        __wasi_mut_args(raw);
+        Box::from_raw(raw)
+    };
+    assert_eq!(*given, *expected);
+}
\ No newline at end of file
diff --git a/wasi-common-cbindgen/tests/no_args.rs b/wasi-common-cbindgen/tests/no_args.rs
new file mode 100644
index 0000000000..af17e04123
--- /dev/null
+++ b/wasi-common-cbindgen/tests/no_args.rs
@@ -0,0 +1,12 @@
+extern crate wasi_common_cbindgen;
+
+pub use wasi_common_cbindgen::wasi_common_cbindgen;
+
+#[wasi_common_cbindgen]
+fn no_args() -> u32 {
+    0
+}
+
+fn main() {
+    assert_eq!(unsafe { __wasi_no_args() }, no_args());
+}
diff --git a/wasi-common-cbindgen/tests/ref_args.rs b/wasi-common-cbindgen/tests/ref_args.rs
new file mode 100644
index 0000000000..72aea6e9d3
--- /dev/null
+++ b/wasi-common-cbindgen/tests/ref_args.rs
@@ -0,0 +1,20 @@
+extern crate wasi_common_cbindgen;
+
+pub use wasi_common_cbindgen::wasi_common_cbindgen;
+
+#[wasi_common_cbindgen]
+fn ref_args(a: &usize) -> usize {
+    a + 1
+}
+
+fn main() {
+    let a = Box::new(2);
+    let expected = ref_args(a.as_ref());
+    let given = unsafe {
+        let raw = Box::into_raw(a);
+        let res = __wasi_ref_args(raw);
+        Box::from_raw(raw);
+        res
+    };
+    assert_eq!(given, expected);
+}
\ No newline at end of file
diff --git a/wasi-common-cbindgen/tests/test.rs b/wasi-common-cbindgen/tests/test.rs
new file mode 100644
index 0000000000..9868f9c543
--- /dev/null
+++ b/wasi-common-cbindgen/tests/test.rs
@@ -0,0 +1,8 @@
+#[test]
+fn tests() {
+    let t = trybuild::TestCases::new();
+    t.pass("tests/no_args.rs");
+    t.pass("tests/val_args.rs");
+    t.pass("tests/ref_args.rs");
+    t.pass("tests/mut_args.rs");
+}
\ No newline at end of file
diff --git a/wasi-common-cbindgen/tests/val_args.rs b/wasi-common-cbindgen/tests/val_args.rs
new file mode 100644
index 0000000000..e90509b0de
--- /dev/null
+++ b/wasi-common-cbindgen/tests/val_args.rs
@@ -0,0 +1,12 @@
+extern crate wasi_common_cbindgen;
+
+pub use wasi_common_cbindgen::wasi_common_cbindgen;
+
+#[wasi_common_cbindgen]
+fn val_args(a: usize, b: usize) -> usize {
+    a + b
+}
+
+fn main() {
+    assert_eq!(unsafe { __wasi_val_args(1, 2) }, val_args(1, 2));
+}
\ No newline at end of file