diff --git a/index.es.js b/index.es.js
index db06f8e..7701301 100644
--- a/index.es.js
+++ b/index.es.js
@@ -378,8 +378,10 @@ class SharedMap {
                 this.stats.collisions++;
                 /* Replacing existing key */
                 if (this._match(key, pos)) {
-                    for (let i = 0; i < value.length; i++)
+                    let i;
+                    for (i = 0; i < value.length; i++)
                         this.valuesData[pos * this.meta[META.objSize] + i] = value.charCodeAt(i);
+                    this.valuesData[pos * this.meta[META.objSize] + i] = 0;
                     exclusive || this._unlockLine(slidingLock);
                     return;
                 }
diff --git a/index.js b/index.js
index f6bf401..c0e2171 100644
--- a/index.js
+++ b/index.js
@@ -379,8 +379,10 @@ export default class SharedMap {
                 this.stats.collisions++;
                 /* Replacing existing key */
                 if (this._match(key, pos)) {
-                    for (let i = 0; i < value.length; i++)
+                    let i;
+                    for (i = 0; i < value.length; i++)
                         this.valuesData[pos * this.meta[META.objSize] + i] = value.charCodeAt(i);
+                    this.valuesData[pos * this.meta[META.objSize] + i] = 0;
                     exclusive || this._unlockLine(slidingLock);
                     return;
                 }
diff --git a/index.umd.js b/index.umd.js
index c101d20..13201b0 100644
--- a/index.umd.js
+++ b/index.umd.js
@@ -384,8 +384,10 @@
                    this.stats.collisions++;
                    /* Replacing existing key */
                    if (this._match(key, pos)) {
-                       for (let i = 0; i < value.length; i++)
+                       let i;
+                       for (i = 0; i < value.length; i++)
                            this.valuesData[pos * this.meta[META.objSize] + i] = value.charCodeAt(i);
+                       this.valuesData[pos * this.meta[META.objSize] + i] = 0;
                        exclusive || this._unlockLine(slidingLock);
                        return;
                    }