diff --git a/Cargo.toml b/Cargo.toml
index 64552d11..f859dcee 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,12 +17,17 @@ generic-array = "0.8.2"
 lazy_static = "0.2.8"
 libc = "0.2"
 matches = "0.1.6"
-region = "0.0.6"
 slice-pool = "0.3.3"
 
+[dependencies.region]
+git = "https://github.com/darfink/region-rs.git"
+
 [dependencies.mmap]
 git = "https://github.com/retep998/rust-mmap.git"
 
+[dev-dependencies]
+volatile_cell = "1.0.0"
+
 [target]
 
 [target."cfg(any(target_arch = \"x86\", target_arch = \"x86_64\"))".dependencies]
diff --git a/tests/lib.rs b/tests/lib.rs
index 5b61d14d..05ecd838 100644
--- a/tests/lib.rs
+++ b/tests/lib.rs
@@ -1,14 +1,18 @@
 extern crate detour;
+extern crate volatile_cell;
 use std::mem;
+use volatile_cell::VolatileCell;
 
 type FnAdd = extern "C" fn(i32, i32) -> i32;
 
+#[inline(never)]
 extern "C" fn add(x: i32, y: i32) -> i32 {
-    x + y
+    VolatileCell::new(x).get() + y
 }
 
+#[inline(never)]
 extern "C" fn sub_detour(x: i32, y: i32) -> i32 {
-    x - y
+    VolatileCell::new(x).get() - y
 }
 
 #[test]