diff --git a/third-party/wasmi/crates/wasmi/src/tracer/mod.rs b/third-party/wasmi/crates/wasmi/src/tracer/mod.rs
index 8c026e1..2d26d8e 100644
--- a/third-party/wasmi/crates/wasmi/src/tracer/mod.rs
+++ b/third-party/wasmi/crates/wasmi/src/tracer/mod.rs
@@ -147,8 +147,9 @@ impl Tracer {
             .max();
 
         // Truncate to the largest 8-byte chunk that can accommodate the used highest address.
-        let new_len = highest_address.map_or(0, |addr| (addr / 7) + 1);
-
+        let new_len = highest_address.map_or(0, |addr| (addr / 8) + 1);
+        // Add an extra slot because reads and writes also access the next chunk (Q)
+        let new_len = new_len + 1;
         self.IS_mem.truncate(new_len as usize);
 
         self.execution_trace