diff --git a/lib/src/compiler/context.rs b/lib/src/compiler/context.rs
index aa9a0571..bc7f86f5 100644
--- a/lib/src/compiler/context.rs
+++ b/lib/src/compiler/context.rs
@@ -189,9 +189,7 @@ impl VarStack {
         self.used += capacity;
         self.frame_id += 1;
 
-        if self.used * Var::mem_size()
-            > wasm::VARS_STACK_END - wasm::VARS_STACK_START
-        {
+        if self.used > wasm::MAX_VARS {
             panic!("variables stack overflow");
         }
 
@@ -273,9 +271,7 @@ impl Var {
         if self.index >= from_index {
             self.index += shift_amount;
         }
-        if self.index * Var::mem_size()
-            >= wasm::VARS_STACK_END - wasm::VARS_STACK_START
-        {
+        if self.index >= wasm::MAX_VARS {
             panic!("variables stack overflow during shift");
         }
     }