diff --git a/Makefile b/Makefile
index 7634553..9bfd025 100644
--- a/Makefile
+++ b/Makefile
@@ -2,12 +2,12 @@
 
 PACKAGE_VERSION = 2.0
 
-CC = gcc
-CXX = g++
+CC ?= gcc
+CXX ?= g++
 EXEEXT =
-PKG_CONFIG=pkg-config
-CFLAGS   = -Wall -O2
-LDFLAGS  = -Wall -O2 -lm
+PKG_CONFIG?=pkg-config
+CFLAGS   ?= -Wall -O2
+LDFLAGS  ?= -Wall -O2
 GTK      = 3
 
 COBJS    = main-command.o unixtime.o gpx-read.o correlate.o exif-gps.o latlong.o
@@ -20,6 +20,7 @@ CFLAGSINC = `$(PKG_CONFIG) --cflags libxml-2.0 exiv2`
 GTKFLAGS  = `$(PKG_CONFIG) --cflags gtk+-$(GTK).0`
 LIBS      = `$(PKG_CONFIG) --libs libxml-2.0 exiv2`
 LIBSGUI   = `$(PKG_CONFIG) --libs gtk+-$(GTK).0`
+LIBS      += -lm -lstdc++
 
 CFLAGSINC += $(GTKFLAGS)