diff --git a/src/ttables.h b/src/ttables.h
index 7dc43b3..f915d61 100644
--- a/src/ttables.h
+++ b/src/ttables.h
@@ -78,7 +78,9 @@ class TTable {
   }
 
   inline void Increment(const unsigned e, const unsigned f, const double x) {
-    counts[e].find(f)->second += x; // Ignore race conditions here.
+// Each thread locks only the part of the table which is writing on. Other threads have access to the rest of the table to update!
+#pragma omp atomic
+    counts[e].find(f)->second += x;.
   }
 
   void NormalizeVB(const double alpha) {