diff --git a/Makefile b/Makefile
index 2de47b197..46a33b4ba 100644
--- a/Makefile
+++ b/Makefile
@@ -35,6 +35,7 @@ all:
 	@echo "check-fast - compile and execute test suite (skip long-running tests)"
 	@echo "clean - remove built files"
 	@echo "coverage - create coverage information with lcov"
+	@echo "coverage-fast - create coverage information with fastcov"
 	@echo "cppcheck - analyze code with cppcheck"
 	@echo "cpplint - analyze code with cpplint"
 	@echo "clang_tidy - analyze code with Clang-Tidy"
@@ -82,13 +83,13 @@ coverage:
 	cd build_coverage ; ninja lcov_html
 	open build_coverage/test/html/index.html
 
-fast-cov:
+coverage-fast:
 	rm -fr build_coverage
 	mkdir build_coverage
 	cd build_coverage ; CXX=$(COMPILER_DIR)/g++ cmake .. -GNinja -DJSON_Coverage=ON -DJSON_MultipleHeaders=ON
 	cd build_coverage ; ninja
 	cd build_coverage ; ctest -E '.*_default' -j10
-	cd build_coverage ; ninja lcov_html2
+	cd build_coverage ; ninja fastcov_html
 	open build_coverage/test/html/index.html
 
 ##########################################################################
diff --git a/README.md b/README.md
index f05af4405..ee0e249f2 100644
--- a/README.md
+++ b/README.md
@@ -1279,9 +1279,11 @@ The library itself consists of a single header file licensed under the MIT licen
 - [**doctest**](https://github.com/onqtam/doctest) for the unit tests
 - [**Doozer**](https://doozer.io) for [continuous integration](https://doozer.io/nlohmann/json) on Linux (CentOS, Raspbian, Fedora)
 - [**Doxygen**](http://www.stack.nl/~dimitri/doxygen/) to generate [documentation](https://nlohmann.github.io/json/)
+- [**fastcov**](https://github.com/RPGillespie6/fastcov) to process coverage information
 - [**git-update-ghpages**](https://github.com/rstacruz/git-update-ghpages) to upload the documentation to gh-pages
 - [**GitHub Changelog Generator**](https://github.com/skywinder/github-changelog-generator) to generate the [ChangeLog](https://github.com/nlohmann/json/blob/develop/ChangeLog.md)
 - [**Google Benchmark**](https://github.com/google/benchmark) to implement the benchmarks
+- [**lcov**](http://ltp.sourceforge.net/coverage/lcov.php) to process coverage information and create a HTML view
 - [**libFuzzer**](http://llvm.org/docs/LibFuzzer.html) to implement fuzz testing for OSS-Fuzz
 - [**OSS-Fuzz**](https://github.com/google/oss-fuzz) for continuous fuzz testing of the library ([project repository](https://github.com/google/oss-fuzz/tree/master/projects/json))
 - [**Probot**](https://probot.github.io) for automating maintainer tasks such as closing stale issues, requesting missing information, or detecting toxic comments.
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 1a816dbf0..b73dfc9ad 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -27,9 +27,9 @@ endif()
 
 if(JSON_Coverage)
     message(STATUS "Building test suite with coverage information")
-    #if(NOT "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
-    #    message(FATAL_ERROR "JSON_Coverage requires GCC.")
-    #endif()
+    if(NOT "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+        message(FATAL_ERROR "JSON_Coverage requires GCC.")
+    endif()
 
     # enable profiling
     set(CMAKE_CXX_FLAGS "--coverage -g -O0 -fprofile-arcs -ftest-coverage")
@@ -46,18 +46,16 @@ if(JSON_Coverage)
     # (filter script from https://stackoverflow.com/a/43726240/266378)
     add_custom_target(lcov_html
         COMMAND lcov --directory . --capture --output-file json.info --rc lcov_branch_coverage=1
-        COMMAND lcov -e json.info ${SOURCE_FILES} --output-file json.info.filtered --rc lcov_branch_coverage=1
+        COMMAND lcov -e json.info ${SOURCE_FILES} --output-file json.info.filtered --gcov-tool ${GCOV_BIN} --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"
     )
 
-    # add target to collect coverage information and generate HTML file
-    # (filter script from https://stackoverflow.com/a/43726240/266378)
-    add_custom_target(lcov_html2
+    add_custom_target(fastcov_html
         COMMAND ${CMAKE_SOURCE_DIR}/test/thirdparty/fastcov/fastcov.py --branch-coverage --lcov -o json.info --gcov ${GCOV_BIN} --compiler-directory ${CMAKE_BINARY_DIR} --source-files ${SOURCE_FILES}
-        COMMAND ${CMAKE_SOURCE_DIR}/test/thirdparty/imapdl/filterbr.py json.info > 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
+        COMMAND ${CMAKE_SOURCE_DIR}/test/thirdparty/imapdl/filterbr.py json.info > json.info.noexcept
+        COMMAND genhtml --title "JSON for Modern C++" --legend --demangle-cpp --output-directory html --show-details --branch-coverage json.info.noexcept
         COMMENT "Generating HTML report test/html/index.html"
     )
 endif()