Improve warning message

https://github.com/ruby/ruby/pull/2637#discussion_r341812475

1 files changed, 2 insertions, 2 deletions

diff --git a/spec/ruby/core/regexp/match_spec.rb b/spec/ruby/core/regexp/match_spec.rb
index 8297be1c1d..e2075d1dc0 100644
--- a/spec/ruby/core/regexp/match_spec.rb
+++ b/spec/ruby/core/regexp/match_spec.rb
@@ -100,7 +100,7 @@ describe "Regexp#match" do
 
   ruby_version_is "2.7"..."3.0" do
     it "warns the deprecation when the given argument is nil" do
-      -> { /foo/.match(nil) }.should complain(/given argument is nil/)
+      -> { /foo/.match(nil) }.should complain(/given argument is nil; this will raise a TypeError in the next release/)
     end
   end
 
@@ -151,7 +151,7 @@ describe "Regexp#match?" do
 
   ruby_version_is "2.7"..."3.0" do
     it "warns the deprecation" do
-      -> { /./.match?(nil) }.should complain(/given argument is nil/)
+      -> { /./.match?(nil) }.should complain(/given argument is nil; this will raise a TypeError in the next release/)
     end
   end