diff --git a/tests/bison.in b/tests/bison.in
index aedd75d9..f004a571 100644
--- a/tests/bison.in
+++ b/tests/bison.in
@@ -19,7 +19,7 @@
 
 abs_top_srcdir='@abs_top_srcdir@'
 abs_top_builddir='@abs_top_builddir@'
-: ${PERL='@perl@'}
+: ${PERL='@PERL@'}
 
 # Use the shipped files, not those installed.
 BISON_PKGDATADIR=$abs_top_srcdir/data