diff --git a/Cargo.toml b/Cargo.toml
index 14c990d..461c72d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,7 +21,7 @@ all-features = true
 
 [features]
 default = ["backtrace", "safe-shared-libraries"]
-test-support = ["ctor"]
+test-support = ["small_ctor"]
 json = ["serde_json"]
 safe-shared-libraries = ["findshlibs"]
 
@@ -30,9 +30,9 @@ ipc-channel = "0.18.2"
 serde = { version = "1.0.104", features = ["derive"] }
 backtrace = { version = "0.3.43", optional = true, features = ["serde"] }
 libc = "0.2.66"
-ctor = { version = "0.1.20", optional = true }
 serde_json = { version = "1.0.47", optional = true }
 findshlibs = { version = "0.10.2", optional = true }
+small_ctor = { version = "0.1.2", optional = true }
 
 [target."cfg(windows)".dependencies]
 winapi = { version = "0.3.9", features = [
diff --git a/src/testsupport.rs b/src/testsupport.rs
index 4cd25f5..570fd15 100644
--- a/src/testsupport.rs
+++ b/src/testsupport.rs
@@ -9,7 +9,7 @@ static TEST_MODE: AtomicBool = AtomicBool::new(false);
 static TEST_MODULE: AtomicPtr<String> = AtomicPtr::new(std::ptr::null_mut());
 
 // we need this.
-pub use ctor::ctor;
+pub use small_ctor::ctor;
 
 /// Supports the use of procspawn in tests.
 ///
@@ -26,7 +26,7 @@ pub use ctor::ctor;
 macro_rules! enable_test_support {
     () => {
         #[$crate::testsupport::ctor]
-        fn __procspawn_test_support_init() {
+        unsafe fn __procspawn_test_support_init() {
             // strip the crate name from the module path
             let module_path = std::module_path!().splitn(2, "::").nth(1);
             $crate::testsupport::enable(module_path);