diff --git a/Dockerfile b/Dockerfile
index b8f5803..b3fbb69 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,6 +4,7 @@
   build-essential \
   bc \
   m4 \
+  git \
   bison \
   flex \
   python3 \
diff --git a/debs.bzl b/debs.bzl
index c2dfdaf..dbda02a 100644
--- a/debs.bzl
+++ b/debs.bzl
@@ -28,6 +28,7 @@
         "gcc",
         "gcc-6",
         "gcc-6-base",
+        "git",
         "guile-2.0-libs",
         "install-info",
         "lcov",
diff --git a/kunit.sh b/kunit.sh
index 4ef46d8..f3552df 100755
--- a/kunit.sh
+++ b/kunit.sh
@@ -34,7 +34,20 @@
 KUNIT_EXIT_CODE=$?
 
 # Generate an HTML coverage report using LCOV
-lcov -t "kunit_presubmit_tests" -o coverage.info -c -d . > "$ARTIFACTS/lcov.log" 2>&1
+# TODO(mariaignacio): Have LCOV_FILTER be default until we can specify the state
+LCOV_FILTER=1
+
+if [[ $LCOV_FILTER -eq 1 ]]; then
+  # Generate a list of recently modified directories, "-d <dirname> ..."
+  # Note: the final `xargs` joins all the lines together.
+  DIRNAMES=$(git diff --name-only HEAD~ | xargs dirname | sort -u | sed -e 's/^/-d /' | xargs)
+
+  lcov -t "kunit_presubmit_tests" -o coverage.info -c ${DIRNAMES} --no-recursion \
+  > "$ARTIFACTS/lcov.log" 2>&1
+else
+  lcov -t "kunit_presubmit_tests" -o coverage.info -c -d . > "$ARTIFACTS/lcov.log" 2>&1
+fi
+
 genhtml -o "$ARTIFACTS/coverage_html" coverage.info --css-file /lcov/lcov.css > "$ARTIFACTS/genhtml.log" 2>&1
 GENHTML_EXIT_CODE=$?