build: PACKAGE_TARNAME makefile variable should not be overridable
diff --git a/GNUmakefile.in b/GNUmakefile.in
index 8590210f..e97e03e4 100644
--- a/GNUmakefile.in
+++ b/GNUmakefile.in
@@ -6,9 +6,10 @@ export SOURCE_DATE_EPOCH
override SOURCE_DATE_EPOCH_TOUCH := @SOURCE_DATE_EPOCH_TOUCH@
+override PACKAGE_TARNAME := @PACKAGE_TARNAME@
+
prefix := @prefix@
exec_prefix := @exec_prefix@
-PACKAGE_TARNAME := @PACKAGE_TARNAME@
bindir := @bindir@
datarootdir := @datarootdir@
