diff --git a/rkward/rbackend/rpackages/rpackage_install.cmake.in b/rkward/rbackend/rpackages/rpackage_install.cmake.in
index f2772f6d..476a45de 100644
--- a/rkward/rbackend/rpackages/rpackage_install.cmake.in
+++ b/rkward/rbackend/rpackages/rpackage_install.cmake.in
@@ -1,36 +1,36 @@
 SET(DESTDIR $ENV{DESTDIR})
 SET(BUILD_TIMESTAMP "@BUILD_TIMESTAMP@")
 
 MESSAGE(STATUS "Installing R support packages")
 
 IF(NOT ${BUILD_TIMESTAMP} EQUAL "")
 	SET (TIMESTAMPARG "--built-timestamp=${BUILD_TIMESTAMP}")
 ENDIF(NOT ${BUILD_TIMESTAMP} EQUAL "")
 
 IF(WIN32)
 	SET(R_LIBDIR @R_LIBDIR@)
 	IF(DESTDIR)
 		# strip drive letter
 		STRING(REGEX REPLACE "^.:." "" R_LIBDIR ${R_LIBDIR})
 		SET(R_LIBDIR "${DESTDIR}/${R_LIBDIR}")
 		FILE(MAKE_DIRECTORY "${R_LIBDIR}")
 	ENDIF(DESTDIR)
 	EXECUTE_PROCESS(
 		COMMAND @R_EXECUTABLE@ CMD INSTALL ${TIMESTAMPARG} -c -l ${R_LIBDIR} "@CMAKE_CURRENT_SOURCE_DIR@/rkward" "@CMAKE_CURRENT_SOURCE_DIR@/rkwardtests"
-		WORKING_DIRECTORY @CMAKE_CURRENT_BINARY_DIR@
+		WORKING_DIRECTORY "@CMAKE_CURRENT_BINARY_DIR@"
 		RESULT_VARIABLE R_LIB_INSTALL_EXIT_CODE
 	)
 ELSE(WIN32)
 	EXECUTE_PROCESS(
-		COMMAND mkdir -p @CMAKE_CURRENT_BINARY_DIR@/tmp ${DESTDIR}/@R_LIBDIR@
+		COMMAND mkdir -p "@CMAKE_CURRENT_BINARY_DIR@/tmp" ${DESTDIR}/@R_LIBDIR@
 	)
 	EXECUTE_PROCESS(
-		COMMAND env TMPDIR=@CMAKE_CURRENT_BINARY_DIR@/tmp @R_EXECUTABLE@ CMD INSTALL ${TIMESTAMPARG} -c -l ${DESTDIR}/@R_LIBDIR@ "@CMAKE_CURRENT_SOURCE_DIR@/rkward" "@CMAKE_CURRENT_SOURCE_DIR@/rkwardtests"
-		WORKING_DIRECTORY @CMAKE_CURRENT_BINARY_DIR@
+		COMMAND env TMPDIR="@CMAKE_CURRENT_BINARY_DIR@/tmp" @R_EXECUTABLE@ CMD INSTALL ${TIMESTAMPARG} -c -l ${DESTDIR}/@R_LIBDIR@ "@CMAKE_CURRENT_SOURCE_DIR@/rkward" "@CMAKE_CURRENT_SOURCE_DIR@/rkwardtests"
+		WORKING_DIRECTORY "@CMAKE_CURRENT_BINARY_DIR@"
 		RESULT_VARIABLE R_LIB_INSTALL_EXIT_CODE
 	)
 ENDIF(WIN32)
 
 IF(R_LIB_INSTALL_EXIT_CODE)
 	MESSAGE (SEND_ERROR "Failed to install R support libraries. Please make sure you have the required permissions.")
 ENDIF(R_LIB_INSTALL_EXIT_CODE)