diff --git a/src/compute_group_group.cpp b/src/compute_group_group.cpp
index 8427f64b95c53efab4505773710048d4d9094c4e..ea1fa0cebf82824d344e2ffc4b1d5b93dd54f12b 100644
--- a/src/compute_group_group.cpp
+++ b/src/compute_group_group.cpp
@@ -141,7 +141,7 @@ void ComputeGroupGroup::interact()
   firstneigh = list->firstneigh;
 
   // loop over neighbors of my atoms
-  // skip if i,j are not in 2 groups
+  // skip if I,J are not in 2 groups
 
   double one[4],all[4];
   one[0] = one[1] = one[2] = one[3] = 0.0;