diff --git a/.github/workflows/busted.yml b/.github/workflows/busted.yml
index efef0bd..226d90b 100644
--- a/.github/workflows/busted.yml
+++ b/.github/workflows/busted.yml
@@ -1,3 +1,4 @@
+---
 name: Busted
 
 on: [push, pull_request]
@@ -50,19 +51,27 @@ jobs:
         run: |
           busted -c -v
         env:
-          LD_PRELOAD: ${{ matrix.os == 'ubuntu-latest' && '/usr/lib/x86_64-linux-gnu/libasan.so.6:/usr/lib/x86_64-linux-gnu/libstdc++.so.6:/usr/lib/x86_64-linux-gnu/libubsan.so.1' || '' }}
+          LD_PRELOAD: |-
+            ${{ matrix.os == 'ubuntu-latest' &&
+            '/usr/lib/x86_64-linux-gnu/libasan.so.6:/usr/lib/x86_64-linux-gnu/libstdc++.so.6:/usr/lib/x86_64-linux-gnu/libubsan.so.1'
+            || '' }}
 
       - name: Run gcov
         if: success() && startsWith(matrix.os, 'ubuntu-')
         run: |
           gcov -p -b -s"$(pwd)" -r *.gcda
+          rm -f "kiwi#*.gcov"
 
       - name: generate Lua lcov test reports
-        if: success() && !startsWith(matrix.os, 'windows-') && startsWith(matrix.lua_version, 'luajit-')
+        if: |-
+          success() && !startsWith(matrix.os, 'windows-')
+          && startsWith(matrix.lua_version, 'luajit-')
         run: luacov
 
       - name: Report test coverage
-        if: success() && !startsWith(matrix.os, 'windows-') && (startsWith(matrix.lua_version, 'luajit-') || startsWith(matrix.os, 'ubuntu-'))
+        if: |-
+          success() && !startsWith(matrix.os, 'windows-')
+          && (startsWith(matrix.lua_version, 'luajit-') || startsWith(matrix.os, 'ubuntu-'))
         continue-on-error: true
         uses: coverallsapp/github-action@v2
         with:
diff --git a/Makefile b/Makefile
index 8a8fec2..0c2df78 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ LIBFLAG := -shared
 LIB_EXT := $(if $(filter Windows_NT,$(OS)),dll,so)
 LUA_INCDIR := /usr/include
 
-SRCDIR := $(dir $(realpath $(lastword $(MAKEFILE_LIST))))
+SRCDIR := .
 
 ifeq ($(OS),Windows_NT)
   is_clang = $(filter %clang++,$(CXX))
@@ -29,13 +29,17 @@ SANITIZE_FLAGS := -fsanitize=undefined -fsanitize=address -fsanitize=alignment -
  -fsanitize=shift -fsanitize=unreachable -fsanitize=bool \
  -fsanitize=enum
 
-COVERAGE_FLAGS := -fprofile-arcs -ftest-coverage
+COVERAGE_FLAGS := --coverage
 LTO_FLAGS := -flto=auto
 
 -include config.mk
 
 ifeq ($(origin LUAROCKS), command line)
-  CCFLAGS := $(CFLAGS)
+  ifdef FCOV
+    CCFLAGS := $(patsubst -O%,,$(CFLAGS))
+  else
+    CCFLAGS := $(CFLAGS)
+  endif
   override CFLAGS := -std=c99 $(CCFLAGS)
 
   ifneq ($(filter %gcc,$(CC)),)