diff --git a/tools/build-system/launchpad/sflphone-common-video/debian/rules b/tools/build-system/launchpad/sflphone-common-video/debian/rules
index 53e3a7cb43786ed3f8383569a9be3ded83c84937..c827baa8d747c9927509c8868de0cd3e7a1f488b 100755
--- a/tools/build-system/launchpad/sflphone-common-video/debian/rules
+++ b/tools/build-system/launchpad/sflphone-common-video/debian/rules
@@ -38,7 +38,7 @@ configure-stamp:
 	# Add here commands to configure the package.
 	./autogen.sh
 	./configure --prefix=/usr --enable-video
-	cd libs/pjproject-2.2.1; CFLAGS=-fPIC -O2 -DNDEBUG ./configure $(PJ_CONFIG_OPTIONS)
+	cd libs/pjproject-2.2.1; "CFLAGS=-fPIC -O2 -DNDEBUG" ./configure $(PJ_CONFIG_OPTIONS)
 	touch configure-stamp
 
 #Architecture
diff --git a/tools/build-system/launchpad/sflphone-common/debian/rules b/tools/build-system/launchpad/sflphone-common/debian/rules
index e70513755f9006d6333e135a76a71136e68dc48f..08a56ca76b4b32829df246c427ec08b7937594ee 100755
--- a/tools/build-system/launchpad/sflphone-common/debian/rules
+++ b/tools/build-system/launchpad/sflphone-common/debian/rules
@@ -38,7 +38,7 @@ configure-stamp:
 	# Add here commands to configure the package.
 	./autogen.sh
 	./configure --prefix=/usr
-	cd libs/pjproject-2.2.1; CFLAGS=-fPIC -O2 -DNDEBUG ./configure $(PJ_CONFIG_OPTIONS)
+	cd libs/pjproject-2.2.1; "CFLAGS=-fPIC -O2 -DNDEBUG" ./configure $(PJ_CONFIG_OPTIONS)
 	touch configure-stamp
 
 #Architecture