diff --git a/Cargo.toml b/Cargo.toml
index ef48a05..ccb231d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "stacker"
-version = "0.1.20"
+version = "0.1.21"
 edition = "2021"
 rust-version = "1.63"
 authors = ["Alex Crichton <alex@alexcrichton.com>", "Simonas Kazlauskas <stacker@kazlauskas.me>"]
diff --git a/src/lib.rs b/src/lib.rs
index ea58ee9..ee5803c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -91,7 +91,7 @@ pub fn grow<R, F: FnOnce() -> R>(stack_size: usize, callback: F) -> R {
 /// to determine whether a stack switch should be made or not.
 pub fn remaining_stack() -> Option<usize> {
     let current_ptr = current_stack_ptr();
-    get_stack_limit().map(|limit| current_ptr - limit)
+    get_stack_limit().map(|limit| current_ptr.saturating_sub(limit))
 }
 
 psm_stack_information!(