diff --git a/debian/rules b/debian/rules
index 0e93c13..539a537 100755
--- a/debian/rules
+++ b/debian/rules
@@ -25,7 +25,8 @@
 $(info Guessed geos version is $(VER))
 endif
 
-CFLAGS = -Wall -g -fpermissive
+CFLAGS = -Wall -g
+CXX = g++ -fpermissive
 
 ifneq (,$(findstring noopt,$(DEB_BUILD_OPTIONS)))
 	CFLAGS += -O0
@@ -53,7 +54,7 @@
 	mv config.guess config.guess.bak
 	cp -f /usr/share/misc/config.guess config.guess
 endif
-	CFLAGS="$(CFLAGS)" ./configure \
+	CXX="$(CXX)" CFLAGS="$(CFLAGS)" ./configure \
         --host=$(DEB_HOST_GNU_TYPE) \
         --build=$(DEB_BUILD_GNU_TYPE) \
         --enable-ruby \
@@ -69,7 +70,7 @@
 build-arch: build-arch-stamp
 build-arch-stamp:  config.status
 	# Add here commands to compile the arch part of the package.
-	CFLAGS="$(CFLAGS)" $(MAKE)
+	CXX="$(CXX)" CFLAGS="$(CFLAGS)" $(MAKE)
 	touch $@
 
 build-indep: build-indep-stamp