diff --git a/Makefile b/Makefile
index 649948c..2a079dc 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ HDRS := $(filter-out $(LIBNAME).hpp,$(wildcard *.hpp))
 
 CXX ?= g++
 
-CXXFLAGS := $(CXXFLAGS) -Wshadow -Wall -Wpedantic -Wextra -g -fno-strict-aliasing -std=c++17 -fPIC
+CXXFLAGS += -Wshadow -Wall -Wpedantic -Wextra -g -std=c++17 -fPIC
 ifeq ($(DEBUG),1)
 	CXXFLAGS += -D DEBUG -O0
 else
diff --git a/tester/Makefile b/tester/Makefile
index ba6cdc8..f8f3ad8 100644
--- a/tester/Makefile
+++ b/tester/Makefile
@@ -15,7 +15,7 @@ MANDIR ?= $(DATADIR)/man
 RM := /bin/rm -f
 INSTALL := /usr/bin/install -c
 
-CXXFLAGS := $(CXXFLAGS) -Wshadow -Wall -Wpedantic -Wextra -g -fno-strict-aliasing -std=c++17 -pthread
+CXXFLAGS += -Wshadow -Wall -Wpedantic -Wextra -g -std=c++17
 ifeq ($(DEBUG),1)
 	CXXFLAGS += -D DEBUG -O0
 else