diff --git a/src/hashset.asm b/src/hashset.asm
index 5fee078..e1293ed 100644
--- a/src/hashset.asm
+++ b/src/hashset.asm
@@ -78,6 +78,8 @@ pub contains:
     add r9, r2, r3 ; Pointer to bucket
 
         load_32 r3, [r9] ; First hash
+        cmp r3, rz
+        je contains_notfourth ; If hash is zero, no items left to check
         cmp r12, r3
         jne contains_notfirst
         ; First item hash passed - checking equality
@@ -87,6 +89,8 @@ pub contains:
     contains_notfirst:
         add r9, r9, 8
         load_32 r3, [r9] ; Second hash
+        cmp r3, rz
+        je contains_notfourth ; If hash is zero, no items left to check
         cmp r12, r3
         jne contains_notsecond
         ; Second item hash passed - checking equality
@@ -96,6 +100,8 @@ pub contains:
     contains_notsecond:
         add r9, r9, 8
         load_32 r3, [r9] ; Third hash
+        cmp r3, rz
+        je contains_notfourth ; If hash is zero, no items left to check
         cmp r12, r3
         jne contains_notthird
         ; Third item hash passed - checking equality
@@ -105,6 +111,8 @@ pub contains:
     contains_notthird:
         add r9, r9, 8
         load_32 r3, [r9] ; Fourth hash
+        cmp r3, rz
+        je contains_notfourth ; If hash is zero, no items left to check
         cmp r12, r3
         jne contains_notfourth
         ; Fourth item hash passed - checking equality