diff --git a/build/Makefile.vty-reference.inc b/build/Makefile.vty-reference.inc
index 9e22925..878c841 100644
--- a/build/Makefile.vty-reference.inc
+++ b/build/Makefile.vty-reference.inc
@@ -79,7 +79,7 @@ $(GEN_DIR)/docbook_vty.xml: \
 	$(OSMO_GSM_MANUALS_DIR)/build/vty_reference_combine.sh "$(MERGE_DOC)" \
 		$$($(OSMO_GSM_MANUALS_DIR)/build/find_existing_path.sh "vty/*reference.xml" $(builddir) $(srcdir)) \
 		$(OSMO_GSM_MANUALS_DIR)/common/vty_additions.xml \
-		$(srcdir)/vty/*additions*.xml
+		$(srcdir)/vty/*additions*.xml > $(GEN_DIR)/combined.xml
 	xsltproc $(OSMO_GSM_MANUALS_DIR)/vty_reference.xsl $(GEN_DIR)/combined.xml \
 		> $(GEN_DIR)/docbook_vty.xml
 
@@ -98,5 +98,5 @@ $(GEN_DIR)/docbook_%-vty-reference.xml: \
 	$(OSMO_GSM_MANUALS_DIR)/build/vty_reference_combine.sh "$(MERGE_DOC)" \
 		$$($(OSMO_GSM_MANUALS_DIR)/build/find_existing_path.sh "*reference.xml" $$VTYDIR_BUILD $$VTYDIR_SRC) \
 		$(OSMO_GSM_MANUALS_DIR)/common/vty_additions.xml \
-		$$VTYDIR_SRC/*additions*.xml && \
+		$$VTYDIR_SRC/*additions*.xml > $$VTYGEN/combined.xml && \
 	xsltproc $(OSMO_GSM_MANUALS_DIR)/vty_reference.xsl $$VTYGEN/combined.xml > "$@"
diff --git a/build/vty_reference_combine.sh b/build/vty_reference_combine.sh
index 11e84c0..7b19758 100755
--- a/build/vty_reference_combine.sh
+++ b/build/vty_reference_combine.sh
@@ -1,12 +1,9 @@
 #!/bin/sh
 # usage: vty_reference_combine.sh path/to/merge_doc.xsl path/to/*reference.xml [paths to additional xmls]
+# the result of combination is printed to stdout
 # see Makefile.vty-reference.inc
 set -e
 
-# Allow overriding the "generated" output dir, so we don't have collisions when building multiple VTY references in one
-# Osmocom project (OS#4292)
-VTYGEN=${VTYGEN:-generated}
-
 # first argument: merge_doc.xsl
 MERGE_DOC="$1"
 shift
@@ -16,25 +13,29 @@ reference="$1"
 test "$(ls -1 $reference | wc -l)" = "1"
 shift
 
-combined="$VTYGEN/combined.xml"
-combine_src="$VTYGEN/combine_src.xml"
-
 set -x
-cp $reference "$combined"
+
+# we cannot use the same file as input and output, because
+# xsltproc would override the input immediately :/
+combined=$(mktemp)
+combine_src=$(mktemp)
+cp $reference $combined
 
 while [ -n "$1" ]; do
 	addition="$(realpath "$1")"
 	shift
 
-	# Fix permissions: xsltproc sets the output permissions the same as the
-	# input file, which means during "make distcheck" our output file will
-	# become read-only.
-	if [ -f "$combine_src" ]; then
-		chmod 644 "$combine_src"
-	fi
+	# sync both input and output files
+	cp $combined $combine_src
 
-	mv "$combined" "$combine_src"
 	xsltproc -o "$combined" \
 		--stringparam with "$addition" \
 		"$MERGE_DOC" "$combine_src"
 done
+
+# print the results to stdout
+cat $combined >&1
+
+# clean up temporary files
+rm -f $combine_src
+rm -f $combined