diff --git a/.travis.yml b/.travis.yml
index fa2918f35..868ac9978 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -99,7 +99,7 @@ matrix:
     before_script:
       - pip install --user cpp-coveralls
     after_success:
-      - coveralls --build-root test --include single_header/nlohmann --gcov 'gcov-4.9' --gcov-options '\-lp'
+      - coveralls --build-root test --include single_include/nlohmann --gcov 'gcov-4.9' --gcov-options '\-lp'
     env:
       - COMPILER=g++-4.9
       - CMAKE_OPTIONS=-DJSON_Coverage=ON
diff --git a/Makefile b/Makefile
index 30b8ba9ab..1cfa5101b 100644
--- a/Makefile
+++ b/Makefile
@@ -81,7 +81,7 @@ clean:
 
 coverage:
 	mkdir build_coverage
-	cd build_coverage ; CXX=g++-5 cmake .. -GNinja -DJSON_Coverage=ON
+	cd build_coverage ; CXX=g++-5 cmake .. -GNinja -DJSON_Coverage=ON -DJSON_MultipleHeaders=ON
 	cd build_coverage ; ninja
 	cd build_coverage ; ctest -j10
 	cd build_coverage ; ninja lcov_html
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index a4021923e..d53d5c4b3 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -40,11 +40,14 @@ if(JSON_Coverage)
     string(REGEX MATCH "^[0-9]+" GCC_VERSION "${CMAKE_CXX_COMPILER_VERSION}")
     find_program(GCOV_BIN NAMES gcov-${GCC_VERSION} gcov HINTS ${COMPILER_PATH})
 
+    # collect all source files from the chosen include dir
+    file(GLOB_RECURSE SOURCE_FILES ${NLOHMANN_JSON_INCLUDE_BUILD_DIR}*.hpp)
+
     # add target to collect coverage information and generate HTML file
     # (filter script from https://stackoverflow.com/a/43726240/266378)
     add_custom_target(lcov_html
         COMMAND lcov --directory . --capture --output-file json.info --gcov-tool ${GCOV_BIN} --rc lcov_branch_coverage=1
-        COMMAND lcov -e json.info ${CMAKE_SOURCE_DIR}/single_include/nlohmann/json.hpp --output-file json.info.filtered --rc lcov_branch_coverage=1
+        COMMAND lcov -e json.info ${SOURCE_FILES} --output-file json.info.filtered --rc lcov_branch_coverage=1
         COMMAND ${CMAKE_SOURCE_DIR}/test/thirdparty/imapdl/filterbr.py json.info.filtered > json.info.filtered.noexcept
         COMMAND genhtml --title "JSON for Modern C++" --legend --demangle-cpp --output-directory html --show-details --branch-coverage json.info.filtered.noexcept
         COMMENT "Generating HTML report test/html/index.html"