diff --git a/src/librustc_arena/lib.rs b/src/librustc_arena/lib.rs
index bbe80c26dcbf9..725850036bbbf 100644
--- a/src/librustc_arena/lib.rs
+++ b/src/librustc_arena/lib.rs
@@ -386,7 +386,7 @@ impl DroplessArena {
             self.align(align);
 
             let future_end = intrinsics::arith_offset(self.ptr.get(), bytes as isize);
-            if (future_end as *mut u8) >= self.end.get() {
+            if (future_end as *mut u8) > self.end.get() {
                 self.grow(bytes);
             }