diff --git a/src/bitarray.c b/src/bitarray.c
index b751231..d2664d3 100644
--- a/src/bitarray.c
+++ b/src/bitarray.c
@@ -29,10 +29,10 @@ bool bitarrayModify (bitarray* bits, int index, bool set) {
         bit = index % bitsPerWord;
 
     if (set)
-        bits->array[word] |= 1 << bit;
+        bits->array[word] |= 1LL << bit;
 
     else
-        bits->array[word] &= ~(1 << bit);
+        bits->array[word] &= ~(1LL << bit);
 
     return true;
 }
@@ -52,5 +52,5 @@ bitarrayWord bitarrayTest (const bitarray* bits, int index) {
     int word = index / bitsPerWord,
         bit = index % bitsPerWord;
 
-    return bits->array[word] & (1 << bit);
+    return bits->array[word] & (1LL << bit);
 }