diff --git a/GNUmakefile b/GNUmakefile
index a7986bd5..5c73b7b7 100755
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -436,6 +436,9 @@ endif # Gold
 
 # GCC code coverage. Issue 'make coverage'.
 ifneq ($(filter coverage,$(MAKECMDGOALS)),)
+ifeq ($(findstring -DCRYPTOPP_COVERAGE,$(CXXFLAGS)),)
+CXXFLAGS += -DCRYPTOPP_COVERAGE
+endif # -coverage
 ifeq ($(findstring -coverage,$(CXXFLAGS)),)
 CXXFLAGS += -coverage
 endif # -coverage
@@ -574,7 +577,7 @@ coverage: libcryptopp.a cryptest.exe
 	./cryptest.exe v
 	./cryptest.exe tv all
 	lcov --base-directory . --directory . -c -o cryptest.info
-	lcov --remove cryptest.info "*test.*" "bench*.cpp" "validat*.*" "/usr/*" -o cryptest.info
+	lcov --remove cryptest.info "fips140.*" "*test.*" "bench*.cpp" "validat*.*" "/usr/*" -o cryptest.info
 	genhtml -o ./TestCoverage/ -t "cryptest.exe test coverage" --num-spaces 4 cryptest.info
 
 .PHONY: test check