--- a/src/Makefile
+++ b/src/Makefile
@@ -1,7 +1,7 @@
 # In case of windows, use os_cygwin=yes setting in the configuration file (smsd.conf).
 
 # Select your setup size:
-CFLAGS = -D NUMBER_OF_MODEMS=64
+CFLAGS ?= -D NUMBER_OF_MODEMS=64
 
 # Uncomment for Solaris
 # CFLAGS += -D SOLARIS
@@ -43,7 +43,7 @@ smsd: smsd.c extras.o locking.o cfgfile.
 
 ifneq (,$(findstring SOLARIS,$(CFLAGS)))
 ifeq (,$(findstring DISABLE_INET_SOCKET,$(CFLAGS)))
-override LFLAGS += -lsocket -lnsl
+	override LFLAGS += -lsocket -lnsl
 endif
 endif