don't overwrite ldflags/libs env vars

diff --git a/Makefile b/Makefile
index 6a9ccd87284b5a79e89251ba599b01d0e3ed97d0..35b825a1f917a9d0a74898471f54c2a4d2db1d54 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -11,8 +11,8 @@ MINGW   = $(findstring MINGW32, $(UNAME))
 
 CC      ?= clang
 # linker flags and optional additional libraries if required
-LDFLAGS :=
-LIBS    := -lm
+LDFLAGS +=
+LIBS    += -lm
 
 CFLAGS  += -Wall -Wextra -Werror -fno-strict-aliasing $(OPTIONAL)
 ifneq ($(shell git describe --always 2>/dev/null),)