diff --git a/results_latest.txt b/results_latest.txt
index b2779f5..4a50510 100644
--- a/results_latest.txt
+++ b/results_latest.txt
@@ -1,188 +1,188 @@
 Benchmark cycles: 1,000 5,000 10,000 50,000 100,000 500,000 1,000,000 5,000,000
 
 Boolean:
-1,000: 0.001 sec
-5,000: 0.001 sec
+1,000: 0 sec
+5,000: 0.002 sec
 10,000: 0.001 sec
-50,000: 0.003 sec
+50,000: 0.002 sec
 100,000: 0.002 sec
-500,000: 0.01 sec
-1,000,000: 0.021 sec
-5,000,000: 0.106 sec
-Average: 45,972,414 ops/sec
+500,000: 0.008 sec
+1,000,000: 0.016 sec
+5,000,000: 0.082 sec
+Average: 58,991,150 ops/sec
 
 Infinity:
-1,000: 0.001 sec
+1,000: 0 sec
 5,000: 0.001 sec
 10,000: 0.001 sec
 50,000: 0.003 sec
-100,000: 0.004 sec
-500,000: 0.02 sec
-1,000,000: 0.039 sec
-5,000,000: 0.196 sec
-Average: 25,154,717 ops/sec
+100,000: 0.003 sec
+500,000: 0.016 sec
+1,000,000: 0.03 sec
+5,000,000: 0.151 sec
+Average: 32,517,073 ops/sec
 
 NaN:
 1,000: 0 sec
 5,000: 0 sec
-10,000: 0 sec
+10,000: 0.001 sec
 50,000: 0.001 sec
-100,000: 0.003 sec
-500,000: 0.013 sec
-1,000,000: 0.027 sec
-5,000,000: 0.135 sec
-Average: 37,240,223 ops/sec
+100,000: 0.002 sec
+500,000: 0.01 sec
+1,000,000: 0.021 sec
+5,000,000: 0.104 sec
+Average: 47,956,835 ops/sec
 
 null:
-1,000: 0 sec
+1,000: 0.001 sec
 5,000: 0 sec
-10,000: 0 sec
-50,000: 0.002 sec
+10,000: 0.001 sec
+50,000: 0.003 sec
 100,000: 0.002 sec
-500,000: 0.014 sec
-1,000,000: 0.028 sec
-5,000,000: 0.139 sec
-Average: 36,032,432 ops/sec
+500,000: 0.01 sec
+1,000,000: 0.021 sec
+5,000,000: 0.103 sec
+Average: 47,276,596 ops/sec
 
 Number:
 1,000: 0 sec
 5,000: 0 sec
 10,000: 0 sec
-50,000: 0.002 sec
+50,000: 0.001 sec
 100,000: 0.002 sec
-500,000: 0.013 sec
-1,000,000: 0.026 sec
-5,000,000: 0.129 sec
-Average: 38,755,814 ops/sec
+500,000: 0.01 sec
+1,000,000: 0.02 sec
+5,000,000: 0.1 sec
+Average: 50,120,301 ops/sec
 
 String:
 1,000: 0 sec
-5,000: 0 sec
+5,000: 0.001 sec
 10,000: 0.001 sec
-50,000: 0.001 sec
-100,000: 0.002 sec
+50,000: 0.002 sec
+100,000: 0.003 sec
 500,000: 0.01 sec
-1,000,000: 0.021 sec
-5,000,000: 0.104 sec
-Average: 47,956,835 ops/sec
+1,000,000: 0.02 sec
+5,000,000: 0.103 sec
+Average: 47,614,286 ops/sec
 
 undefined:
 1,000: 0 sec
 5,000: 0 sec
-10,000: 0 sec
-50,000: 0.002 sec
+10,000: 0.001 sec
+50,000: 0.001 sec
 100,000: 0.004 sec
-500,000: 0.018 sec
-1,000,000: 0.037 sec
-5,000,000: 0.18 sec
-Average: 27,659,751 ops/sec
+500,000: 0.016 sec
+1,000,000: 0.033 sec
+5,000,000: 0.163 sec
+Average: 30,577,982 ops/sec
 
 Function:
-1,000: 0.001 sec
+1,000: 0 sec
 5,000: 0.001 sec
 10,000: 0.002 sec
-50,000: 0.008 sec
-100,000: 0.016 sec
-500,000: 0.081 sec
-1,000,000: 0.158 sec
-5,000,000: 0.805 sec
-Average: 6,218,284 ops/sec
+50,000: 0.007 sec
+100,000: 0.015 sec
+500,000: 0.073 sec
+1,000,000: 0.146 sec
+5,000,000: 0.728 sec
+Average: 6,858,025 ops/sec
 
 RegExp:
 1,000: 0.001 sec
-5,000: 0.003 sec
+5,000: 0.002 sec
 10,000: 0.006 sec
 50,000: 0.015 sec
 100,000: 0.03 sec
-500,000: 0.149 sec
-1,000,000: 0.297 sec
-5,000,000: 1.488 sec
-Average: 3,351,433 ops/sec
+500,000: 0.146 sec
+1,000,000: 0.294 sec
+5,000,000: 1.468 sec
+Average: 3,397,554 ops/sec
 
 Array:
-1,000: 0.002 sec
-5,000: 0.006 sec
-10,000: 0.009 sec
-50,000: 0.035 sec
-100,000: 0.068 sec
-500,000: 0.34 sec
-1,000,000: 0.673 sec
+1,000: 0.003 sec
+5,000: 0.005 sec
+10,000: 0.012 sec
+50,000: 0.036 sec
+100,000: 0.074 sec
+500,000: 0.367 sec
+1,000,000: 0.699 sec
 5,000,000: 3.331 sec
-Average: 1,493,280 ops/sec
+Average: 1,472,498 ops/sec
 
 Date:
 1,000: 0 sec
-5,000: 0.002 sec
-10,000: 0.002 sec
+5,000: 0.001 sec
+10,000: 0.003 sec
 50,000: 0.01 sec
-100,000: 0.015 sec
-500,000: 0.074 sec
-1,000,000: 0.147 sec
-5,000,000: 0.735 sec
-Average: 6,767,513 ops/sec
+100,000: 0.014 sec
+500,000: 0.072 sec
+1,000,000: 0.144 sec
+5,000,000: 0.718 sec
+Average: 6,929,314 ops/sec
 
 Error:
 1,000: 0.001 sec
 5,000: 0.005 sec
 10,000: 0.013 sec
-50,000: 0.052 sec
-100,000: 0.102 sec
-500,000: 0.498 sec
-1,000,000: 1.017 sec
-5,000,000: 4.996 sec
-Average: 997,307 ops/sec
+50,000: 0.049 sec
+100,000: 0.097 sec
+500,000: 0.483 sec
+1,000,000: 0.966 sec
+5,000,000: 4.899 sec
+Average: 1,023,491 ops/sec
 
 Event:
 1,000: 0.002 sec
-5,000: 0.005 sec
-10,000: 0.009 sec
-50,000: 0.029 sec
+5,000: 0.006 sec
+10,000: 0.008 sec
+50,000: 0.03 sec
 100,000: 0.059 sec
-500,000: 0.293 sec
-1,000,000: 0.586 sec
-5,000,000: 2.935 sec
-Average: 1,701,378 ops/sec
+500,000: 0.291 sec
+1,000,000: 0.582 sec
+5,000,000: 2.913 sec
+Average: 1,713,184 ops/sec
 
 Map:
-1,000: 0.002 sec
-5,000: 0.007 sec
-10,000: 0.007 sec
-50,000: 0.031 sec
-100,000: 0.061 sec
-500,000: 0.308 sec
-1,000,000: 0.613 sec
-5,000,000: 3.083 sec
-Average: 1,621,109 ops/sec
+1,000: 0.001 sec
+5,000: 0.006 sec
+10,000: 0.006 sec
+50,000: 0.03 sec
+100,000: 0.06 sec
+500,000: 0.298 sec
+1,000,000: 0.596 sec
+5,000,000: 2.983 sec
+Average: 1,674,874 ops/sec
 
 Object:
 1,000: 0.003 sec
 5,000: 0.007 sec
 10,000: 0.011 sec
-50,000: 0.056 sec
-100,000: 0.11 sec
-500,000: 0.549 sec
-1,000,000: 1.095 sec
-5,000,000: 5.478 sec
-Average: 912,026 ops/sec
+50,000: 0.055 sec
+100,000: 0.105 sec
+500,000: 0.525 sec
+1,000,000: 1.051 sec
+5,000,000: 5.246 sec
+Average: 951,878 ops/sec
 
 Object (circular):
-1,000: 0.001 sec
+1,000: 0.002 sec
 5,000: 0.007 sec
-10,000: 0.011 sec
-50,000: 0.053 sec
+10,000: 0.01 sec
+50,000: 0.052 sec
 100,000: 0.1 sec
-500,000: 0.504 sec
-1,000,000: 1.009 sec
-5,000,000: 5.032 sec
-Average: 992,407 ops/sec
+500,000: 0.497 sec
+1,000,000: 0.994 sec
+5,000,000: 4.984 sec
+Average: 1,003,009 ops/sec
 
 Set:
 1,000: 0.001 sec
 5,000: 0.006 sec
-10,000: 0.006 sec
-50,000: 0.028 sec
+10,000: 0.007 sec
+50,000: 0.027 sec
 100,000: 0.056 sec
-500,000: 0.279 sec
-1,000,000: 0.559 sec
-5,000,000: 2.798 sec
-Average: 1,785,695 ops/sec
\ No newline at end of file
+500,000: 0.275 sec
+1,000,000: 0.549 sec
+5,000,000: 2.749 sec
+Average: 1,816,349 ops/sec
\ No newline at end of file
diff --git a/src/constants.ts b/src/constants.ts
index fd1e0ab..7b12b8f 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -105,12 +105,12 @@ export type RecursiveClass = keyof typeof RECURSIVE_CLASSES;
 export const HASHABLE_TYPES = {
   bigint: 'i',
   boolean: 'b',
+  empty: 'e',
   function: 'g',
   number: 'n',
   object: 'o',
   string: 's',
   symbol: 's',
-  undefined: 'u',
 } as const;
 
 export type HashableType = keyof typeof HASHABLE_TYPES;
diff --git a/src/stringify.ts b/src/stringify.ts
index e540931..120acd7 100644
--- a/src/stringify.ts
+++ b/src/stringify.ts
@@ -246,7 +246,11 @@ export function stringify(
 ): string {
   const type = typeof value;
 
-  if (type === 'object' && value) {
+  if (value == null || type === 'undefined') {
+    return HASHABLE_TYPES.empty + value;
+  }
+
+  if (type === 'object') {
     return stringifyComplexType(
       value,
       toString.call(value) as unknown as Class,
@@ -254,8 +258,13 @@ export function stringify(
     );
   }
 
-  return (
-    HASHABLE_TYPES[type] +
-    (type === 'function' || type === 'symbol' ? value.toString() : value)
-  );
+  if (type === 'function' || type === 'symbol') {
+    return HASHABLE_TYPES[type] + value.toString();
+  }
+
+  if (type === 'boolean') {
+    return HASHABLE_TYPES.boolean + +value;
+  }
+
+  return HASHABLE_TYPES[type] + value;
 }