diff --git a/ruby.spec b/ruby.spec
index 57bc909..4edab7f 100644
--- a/ruby.spec
+++ b/ruby.spec
@@ -465,6 +465,9 @@ rm -rf ext/fiddle/libffi*
 %patch7 -p1
 %patch8 -p1
 
+# Allow to use autoconf 2.63.
+sed -i '/AC_PREREQ/ s/(.*)/(2.62)/' configure.in
+
 # Provide an example of usage of the tapset:
 cp -a %{SOURCE3} .