diff --git a/src/BitSet.ts b/src/BitSet.ts
index 9d9cd1e..a63ceb0 100644
--- a/src/BitSet.ts
+++ b/src/BitSet.ts
@@ -489,7 +489,7 @@ export default class BitSet
     {
         index = index|0;
 
-        return ((this.words[index >>> WORD_LOG] >>> index) & ONE)|0
+        return (index >= this._length ? ZERO : (this.words[index >>> WORD_LOG] >>> index) & ONE)|0
     }
 
     /**
@@ -910,7 +910,7 @@ export default class BitSet
      *
      * @returns this.
      */
-    public trimTrailingBits(): BitSet
+    private trimTrailingBits(): BitSet
     {
         const wordsLength = this.words.length|0;
         const diff        = (wordsLength*WORD_SIZE - this._length)|0;
diff --git a/test/unit/BitSet.spec.ts b/test/unit/BitSet.spec.ts
index c344516..6578caf 100644
--- a/test/unit/BitSet.spec.ts
+++ b/test/unit/BitSet.spec.ts
@@ -1046,26 +1046,6 @@ describe('trim', () =>
     });
 });
 
-describe('trimTrailingBits', () =>
-{
-    it('should return set, bitstring or full bitstring depending on mode', () =>
-    {
-        const bs  = BitSet.create(55).add(9).add(14).add(50);
-
-        bs.words[1] |= (1 << 60); // set a 1 at index 60 the unofficial way :-)
-
-        const str = bs.toString(-1);
-
-        expect(str).to.eql('0001000000000100000000000000000000000000000000000100001000000000');
-        expect(str.length).to.eql(64);
-        expect(bs.length).to.eql(55);
-
-        bs.trimTrailingBits();
-
-        expect(bs.toString(-1)).to.eql('0000000000000100000000000000000000000000000000000100001000000000');
-    });
-});
-
 describe('union', () =>
 {
     it('should calculate the union of 2 sets', () =>