diff --git a/proc.c b/proc.c
index 558304fb7f..57628c86f1 100644
--- a/proc.c
+++ b/proc.c
@@ -710,7 +710,7 @@ proc_new(VALUE klass, int8_t is_lambda)
                 rb_raise(rb_eArgError, proc_without_block);
             }
             else {
-		rb_warn(proc_without_block);
+		rb_warn("Capturing the given block using Proc.new is deprecated; use `&block` instead");
 	    }
 	}
 #else
diff --git a/spec/ruby/core/kernel/proc_spec.rb b/spec/ruby/core/kernel/proc_spec.rb
index 2c0e7988f9..8c56946874 100644
--- a/spec/ruby/core/kernel/proc_spec.rb
+++ b/spec/ruby/core/kernel/proc_spec.rb
@@ -56,7 +56,7 @@ describe "Kernel#proc" do
 
       -> {
         some_method { "hello" }
-      }.should complain(/tried to create Proc object without a block/)
+      }.should complain(/Capturing the given block using Proc.new is deprecated/)
     end
   end
 
diff --git a/spec/ruby/core/proc/new_spec.rb b/spec/ruby/core/proc/new_spec.rb
index 1c37c64478..7579bfe1b6 100644
--- a/spec/ruby/core/proc/new_spec.rb
+++ b/spec/ruby/core/proc/new_spec.rb
@@ -194,11 +194,11 @@ describe "Proc.new without a block" do
 
   ruby_version_is "2.7" do
     it "can be created if invoked from within a method with a block" do
-      lambda { ProcSpecs.new_proc_in_method { "hello" } }.should complain(/tried to create Proc object without a block/)
+      lambda { ProcSpecs.new_proc_in_method { "hello" } }.should complain(/Capturing the given block using Proc.new is deprecated/)
     end
 
     it "can be created if invoked on a subclass from within a method with a block" do
-      lambda { ProcSpecs.new_proc_subclass_in_method { "hello" } }.should complain(/tried to create Proc object without a block/)
+      lambda { ProcSpecs.new_proc_subclass_in_method { "hello" } }.should complain(/Capturing the given block using Proc.new is deprecated/)
     end
 
 
@@ -209,7 +209,7 @@ describe "Proc.new without a block" do
 
       -> {
         some_method { "hello" }
-      }.should complain(/tried to create Proc object without a block/)
+      }.should complain(/Capturing the given block using Proc.new is deprecated/)
     end
   end
 end