diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index e2629e32..45610257 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -69,6 +69,7 @@ jobs:
           cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ \
                 -DUSE_LUA=ON -DENABLE_BUILD_PROTOBUF=OFF \
                 -DENABLE_INTERNAL_TESTS=ON -DENABLE_LAPI_TESTS=ON \
+                -DENABLE_COV=ON \
                 -G Ninja -S . -B build
         if: ${{ matrix.LUA == 'lua' }}
 
@@ -77,6 +78,7 @@ jobs:
           cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ \
                 -DUSE_LUAJIT=ON -DENABLE_BUILD_PROTOBUF=OFF \
                 -DENABLE_INTERNAL_TESTS=ON -DENABLE_LAPI_TESTS=ON \
+                -DENABLE_COV=ON \
                 -G Ninja -S . -B build
         if: ${{ matrix.LUA == 'luajit' }}
 
diff --git a/cmake/BuildLuaJIT.cmake b/cmake/BuildLuaJIT.cmake
index 021b3d5d..28630f22 100644
--- a/cmake/BuildLuaJIT.cmake
+++ b/cmake/BuildLuaJIT.cmake
@@ -130,6 +130,7 @@ macro(build_luajit LJ_VERSION)
     set(LUA_LIBRARIES bundled-liblua)
     set(LUA_INCLUDE_DIR ${LJ_SOURCE_DIR}/src/)
     set(LUA_VERSION_STRING "LuaJIT ${LJ_VERSION}")
+    set(LUA_SOURCE_DIR ${LJ_SOURCE_DIR})
 
     unset(LJ_SOURCE_DIR)
     unset(LJ_BINARY_DIR)
diff --git a/cmake/BuildLuzer.cmake b/cmake/BuildLuzer.cmake
index a55e7ce3..292227b9 100644
--- a/cmake/BuildLuzer.cmake
+++ b/cmake/BuildLuzer.cmake
@@ -17,6 +17,14 @@ list(APPEND LUZER_CMAKE_FLAGS
     "-DLUA_INCLUDE_DIR=${LUA_INCLUDE_DIR}"
     "-DLUA_LIBRARIES=${LUA_LIBRARIES_LOCATION}"
 )
+# Prevents an error on loading `luzer_impl.so` due to undefined
+# symbol `llvm_gcda_summary_info`.
+if(ENABLE_COV)
+  list(APPEND LUZER_CMAKE_FLAGS
+      -DCMAKE_C_FLAGS=-fprofile-instr-generate
+      -DCMAKE_CXX_FLAGS=-fprofile-instr-generate
+  )
+endif()
 if(USE_LUAJIT)
     list(APPEND LUZER_CMAKE_FLAGS
         "-DLUAJIT_FRIENDLY_MODE=ON"
diff --git a/cmake/CodeCoverage.cmake b/cmake/CodeCoverage.cmake
index 0ec887f4..9d004cfe 100644
--- a/cmake/CodeCoverage.cmake
+++ b/cmake/CodeCoverage.cmake
@@ -18,7 +18,7 @@ endif()
 
 # See https://gcovr.com/en/stable/manpage.html.
 set(GCOVR_OPTIONS
-  --branches
+  --txt-metric branch
   --cobertura ${COVERAGE_XML_REPORT}
   --decisions
   --gcov-executable "llvm-cov gcov"
@@ -29,7 +29,7 @@ set(GCOVR_OPTIONS
   --output ${COVERAGE_HTML_REPORT}
   --print-summary
   --root ${LUA_SOURCE_DIR}
-  --sort-percentage
+  --sort-key uncovered-percent
 )
 
 if(USE_LUA)