diff --git a/build.rs b/build.rs
index f1b0a3046..6284b7e3e 100644
--- a/build.rs
+++ b/build.rs
@@ -192,9 +192,9 @@ fn has_small_stack(_: &Target) -> Result<bool, Box<dyn Error>> {
         // build.rs is executed on the main thread, so we are getting the main thread's stack size.
         // Modern macOS versions default to an 8 MiB main stack but legacy OS X have a 0.5 MiB one.
         let stack_size = unsafe { pthread_get_stacksize_np(pthread_self()) };
-        const TWO_MIB: usize = 2 * 1024 * 1024;
+        const TWO_MIB: usize = 2 * 1024 * 1024 - 1;
         match stack_size {
-            0..TWO_MIB => Ok(true),
+            0..=TWO_MIB => Ok(true),
             _ => Ok(false),
         }
     }