diff --git a/.gitignore b/.gitignore
index e85cfd0f90d..8a7b8ebff0d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,6 +22,7 @@ examples/output.txt
 # ignore coverage files
 .coverage
 .noseids
+htmlcov
 # ignore trajectory offset caches
 .adk_oplsaa.trr_offsets.pkl
 .adk_oplsaa.xtc_offsets.pkl