diff --git a/rubygem-rdiscount.spec b/rubygem-rdiscount.spec
index a8c6ef5..e39d806 100644
--- a/rubygem-rdiscount.spec
+++ b/rubygem-rdiscount.spec
@@ -41,9 +41,6 @@ gem unpack %{SOURCE0}
 %setup -q -D -T -n  %{gem_name}-%{version}
 gem spec %{SOURCE0} -l --ruby | sed -e 's|,|,\n|g' > %{gem_name}.gemspec
 
-sed -i ext/extconf.rb \
-	-e '\@check_sizeof@s| == 4|== size|'
-
 # Remove c and header file to not bundle discount-sources
 (cd ext; ls -1 *.c *.h | grep -v rdiscount.c ) > discount_files