diff -Nrup a/Makefile b/Makefile
--- a/Makefile	2019-03-19 14:21:34.000000000 +0100
+++ b/Makefile	2019-04-05 09:55:58.713659214 +0200
@@ -29,6 +29,8 @@ VPATH=$(srcdir)
 INSTALL = install
 TAR = tar
 
+ENV_CFLAGS := $(CFLAGS)
+
 GCC_WARNINGS1=-Wall -Wpointer-arith -Wstrict-prototypes
 GCC_WARNINGS2=-Wmissing-prototypes -Wmissing-declarations
 GCC_WARNINGS3=-Wno-unused-function -Wno-unused-label -Wno-format-zero-length
@@ -43,7 +45,7 @@ CFLAGS += -pthread
 CPPFLAGS += -DTHREADS
 
 # Optimizing for speed. Comment this out for distribution builds
-CFLAGS += -march=native
+#CFLAGS += -march=native
 
 # To enable debugging of the Yacc grammar, uncomment the following line
 #CPPFLAGS += -DYYDEBUG=1
@@ -83,7 +85,7 @@ CFLAGS += -O2
 # CFLAGS += -g
 # Test coverage flags
 # CFLAGS += -ftest-coverage -fprofile-arcs
-CFLAGS += $(EXTRA_CFLAGS)
+CFLAGS += $(EXTRA_CFLAGS) $(ENV_CFLAGS)
 
 #YFLAGS= --report=all
 LFLAGS=