diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index c2c9c9c..7f1f11a 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -119,6 +119,7 @@ jobs:
           cd signal-hook-registry
           sed -i -e '/signal-hook =/d' Cargo.toml
           sed -i -e 's/libc = "^0.2"/libc = "=0.2.156"/' Cargo.toml
+          sed -i -e 's/errno = ">=0.2, <0.4"/errno = "0.2"/' Cargo.toml
           cargo check
 
   ancient:
@@ -144,6 +145,7 @@ jobs:
         run: |
           rm Cargo.lock
           sed -i -e 's/libc = "^0.2"/libc = "=0.2.156"/' Cargo.toml
+          sed -i -e 's/errno = ">=0.2, <0.4"/errno = "0.2"/' signal-hook-registry/Cargo.toml
           cargo update
           cargo check --no-default-features
 
diff --git a/Cargo.lock b/Cargo.lock
index 2f89342..b761b1b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -826,6 +826,7 @@ dependencies = [
 name = "signal-hook-registry"
 version = "1.4.7"
 dependencies = [
+ "errno",
  "libc",
  "signal-hook",
 ]
diff --git a/ci-check.sh b/ci-check.sh
index fc418c2..8faae4f 100755
--- a/ci-check.sh
+++ b/ci-check.sh
@@ -12,6 +12,7 @@ rm -f Cargo.lock
 if [ "$RUST_VERSION" = 1.36.0 ] || [ "$RUST_VERSION" = 1.40.0 ] ; then
 	sed -i -e 's/libc = "^0.2"/libc = "=0.2.156"/' Cargo.toml
 	sed -i -e 's/cc = { version = "^1"/cc = { version = "=1.0.79"/' Cargo.toml
+	sed -i -e 's/errno = ">=0.2, <0.4"/errno = "0.2"/' signal-hook-registry/Cargo.toml
 fi
 
 cargo build --all --exclude signal-hook-async-std --exclude signal-hook-tokio
diff --git a/signal-hook-registry/Cargo.toml b/signal-hook-registry/Cargo.toml
index 46919f4..cfee92e 100644
--- a/signal-hook-registry/Cargo.toml
+++ b/signal-hook-registry/Cargo.toml
@@ -20,6 +20,7 @@ maintenance = { status = "actively-developed" }
 
 [dependencies]
 libc = "^0.2"
+errno = ">=0.2, <0.4"
 
 [dev-dependencies]
 signal-hook = { version = "~0.3", path = ".." }
diff --git a/signal-hook-registry/src/lib.rs b/signal-hook-registry/src/lib.rs
index 1ba8d43..e791813 100644
--- a/signal-hook-registry/src/lib.rs
+++ b/signal-hook-registry/src/lib.rs
@@ -62,6 +62,7 @@
 //! [signal-hook]: https://docs.rs/signal-hook
 //! [async-signal-safe]: http://www.man7.org/linux/man-pages/man7/signal-safety.7.html
 
+extern crate errno;
 extern crate libc;
 
 mod half_lock;
@@ -78,6 +79,7 @@ use std::sync::atomic::{AtomicPtr, Ordering};
 use std::sync::ONCE_INIT;
 use std::sync::{Arc, Once};
 
+use errno::Errno;
 #[cfg(not(windows))]
 use libc::{c_int, c_void, sigaction, siginfo_t};
 #[cfg(windows)]
@@ -338,6 +340,8 @@ impl GlobalData {
 
 #[cfg(windows)]
 extern "C" fn handler(sig: c_int) {
+    let _errno = ErrnoGuard::new();
+
     if sig != SIGFPE {
         // Windows CRT `signal` resets handler every time, unless for SIGFPE.
         // Reregister the handler to retain maximal compatibility.
@@ -385,6 +389,8 @@ extern "C" fn handler(sig: c_int) {
 // cfg_attr is needed because the `allow(clippy::lint)` syntax was added in Rust 1.31
 #[cfg_attr(clippy, allow(clippy::incompatible_msrv))]
 extern "C" fn handler(sig: c_int, info: *mut siginfo_t, data: *mut c_void) {
+    let _errno = ErrnoGuard::new();
+
     let globals = GlobalData::get();
     let fallback = globals.race_fallback.read();
     let sigdata = globals.data.read();
@@ -422,6 +428,20 @@ extern "C" fn handler(sig: c_int, info: *mut siginfo_t, data: *mut c_void) {
     }
 }
 
+struct ErrnoGuard(Errno);
+
+impl ErrnoGuard {
+    fn new() -> Self {
+        ErrnoGuard(errno::errno())
+    }
+}
+
+impl Drop for ErrnoGuard {
+    fn drop(&mut self) {
+        errno::set_errno(self.0);
+    }
+}
+
 /// List of forbidden signals.
 ///
 /// Some signals are impossible to replace according to POSIX and some are so special that this
@@ -834,4 +854,38 @@ mod tests {
         // The next time unregistering does nothing and tells us so.
         assert!(!unregister(signal));
     }
+
+    /// Check that errno is not clobbered by the signal handler.
+    #[test]
+    fn save_restore_errno() {
+        const MAGIC_ERRNO: i32 = 123456;
+        let status = Arc::new(AtomicUsize::new(0));
+        let action = {
+            let status = Arc::clone(&status);
+            move || {
+                errno::set_errno(Errno(MAGIC_ERRNO));
+                status.store(1, Ordering::Relaxed);
+            }
+        };
+        unsafe {
+            register(SIGUSR1, action).unwrap();
+            libc::raise(SIGUSR1);
+        }
+        for _ in 0..10 {
+            // We can't rule out that the raise() or sleep() clobbers errno, so this test isn't
+            // waterproof. But it fails at least sometimes on some platforms if the errno
+            // save/restore is removed. We assert both before and after the sleep for good luck.
+            assert!(errno::errno().0 != MAGIC_ERRNO);
+            thread::sleep(Duration::from_millis(100));
+            assert!(errno::errno().0 != MAGIC_ERRNO);
+            let current = status.load(Ordering::Relaxed);
+            match current {
+                // Not yet
+                0 => continue,
+                // Good, we are done with the correct result
+                _ if current == 1 => return,
+                _ => panic!("Wrong status value {}", current),
+            }
+        }
+    }
 }