diff --git a/config/config.mk b/config/config.mk
index 1d1e9c29da2d..ed85218a61af 100644
--- a/config/config.mk
+++ b/config/config.mk
@@ -667,7 +667,7 @@ EXPAND_MKSHLIB = $(EXPAND_LIBS_EXEC) $(EXPAND_MKSHLIB_ARGS) -- $(MKSHLIB)
 
 ifneq (,$(MOZ_LIBSTDCXX_TARGET_VERSION)$(MOZ_LIBSTDCXX_HOST_VERSION))
 ifneq ($(OS_ARCH),Darwin)
-CHECK_STDCXX = @$(TOOLCHAIN_PREFIX)objdump -p $(1) | grep -e 'GLIBCXX_3\.4\.\(9\|[1-9][0-9]\)' > /dev/null && echo 'TEST-UNEXPECTED-FAIL | check_stdcxx | We do not want these libstdc++ symbols to be used:' && $(TOOLCHAIN_PREFIX)objdump -T $(1) | grep -e 'GLIBCXX_3\.4\.\(9\|[1-9][0-9]\)' && false || true
+CHECK_STDCXX = @$(TOOLCHAIN_PREFIX)objdump -p $(1) | grep -v -e 'GLIBCXX_3\.4\.\(9\|[1-9][0-9]\)' > /dev/null || ( echo 'TEST-UNEXPECTED-FAIL | check_stdcxx | We do not want these libstdc++ symbols to be used:' && $(TOOLCHAIN_PREFIX)objdump -T $(1) | grep -e 'GLIBCXX_3\.4\.\(9\|[1-9][0-9]\)' && false)
 endif
 endif