diff --git a/ftools/BUILD_DIR/Makefile b/ftools/BUILD_DIR/Makefile
index 67c72c4..9940349 100644
--- a/ftools/BUILD_DIR/Makefile
+++ b/ftools/BUILD_DIR/Makefile
@@ -43,8 +43,8 @@ install-BUILD_DIR:
 fixpfiles:
 	@LHEA_DATA=${HD_TOP_REFDATA}; LHEA_HELP=${HD_TOP_HELP}; \
 	export LHEA_DATA; export LHEA_HELP; \
-	if [ -d ${HD_PFILES} ]; then \
-		cd ${HD_PFILES}; lhea-fixpfiles; \
+	if [ -d "${DESTDIR}"/${HD_PFILES} ]; then \
+		cd "${DESTDIR}"/${HD_PFILES}; lhea-fixpfiles; \
 	fi
 
 # Specializations for xspec (spectral dir) in case we only have xspec data: