diff --git a/.github/workflows/code_coverage.yml b/.github/workflows/code_coverage.yml
index b05bca0..e9e3798 100644
--- a/.github/workflows/code_coverage.yml
+++ b/.github/workflows/code_coverage.yml
@@ -1,6 +1,10 @@
 name: Code Coverage
 
-on: [pull_request]
+on:
+  pull_request:
+  push:
+    branches:
+      - master
 
 env:
   BUILD_TYPE: Debug
diff --git a/hll/CMakeLists.txt b/hll/CMakeLists.txt
index 97daf6d..e7954c7 100644
--- a/hll/CMakeLists.txt
+++ b/hll/CMakeLists.txt
@@ -35,6 +35,7 @@
 # TODO: would be useful if this didn't need to be reproduced in target_sources(), too
 set(hll_HEADERS "")
 list(APPEND hll_HEADERS "include/hll.hpp;include/AuxHashMap.hpp;include/CompositeInterpolationXTable.hpp")
+list(APPEND hll_HEADERS "include/hll.private.hpp;include/HllSketchImplFactory.hpp")
 list(APPEND hll_HEADERS "include/CouponHashSet.hpp;include/CouponList.hpp")
 list(APPEND hll_HEADERS "include/CubicInterpolation.hpp;include/HarmonicNumbers.hpp;include/Hll4Array.hpp")
 list(APPEND hll_HEADERS "include/Hll6Array.hpp;include/Hll8Array.hpp;include/HllArray.hpp")
@@ -60,6 +61,7 @@
 target_sources(hll
   INTERFACE
     ${CMAKE_CURRENT_SOURCE_DIR}/include/hll.hpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/include/hll.private.hpp
     ${CMAKE_CURRENT_SOURCE_DIR}/include/AuxHashMap.hpp
     ${CMAKE_CURRENT_SOURCE_DIR}/include/CompositeInterpolationXTable.hpp
     ${CMAKE_CURRENT_SOURCE_DIR}/include/CouponHashSet.hpp
@@ -71,6 +73,7 @@
     ${CMAKE_CURRENT_SOURCE_DIR}/include/Hll8Array.hpp
     ${CMAKE_CURRENT_SOURCE_DIR}/include/HllArray.hpp
     ${CMAKE_CURRENT_SOURCE_DIR}/include/HllSketchImpl.hpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/include/HllSketchImplFactory.hpp
     ${CMAKE_CURRENT_SOURCE_DIR}/include/HllUtil.hpp
     ${CMAKE_CURRENT_SOURCE_DIR}/include/RelativeErrorTables.hpp
     ${CMAKE_CURRENT_SOURCE_DIR}/include/coupon_iterator.hpp