diff --git a/src/webassembly/memory.rs b/src/webassembly/memory.rs
index d166c15ff..b8fc6f4a6 100644
--- a/src/webassembly/memory.rs
+++ b/src/webassembly/memory.rs
@@ -26,6 +26,8 @@ pub struct LinearMemory {
     // to set a maximum.
     maximum: Option<u32>,
 
+    // The size of the extra guard pages after the end.
+    // Is used to optimize loads and stores with constant offsets.
     offset_guard_size: usize,
 }