diff --git a/CHANGELOG b/CHANGELOG
index f4c05d35..22ed0a18 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,7 @@
 = master
 
+* Warn when defining method that expects 1 argument when block requires multiple arguments when :check_arity option is set to :warn (jeremyevans)
+
 * Implement the match_hooks plugin using the match_hook_args plugin (jeremyevans)
 
 = 3.71.0 (2023-08-14)
diff --git a/lib/roda.rb b/lib/roda.rb
index e2a76594..95cfcdd8 100644
--- a/lib/roda.rb
+++ b/lib/roda.rb
@@ -88,6 +88,7 @@ def define_roda_method(meth, expected_arity, &block)
           end
           call_meth = meth
 
+          # RODA4: Switch to false # :warn in last Roda 3 version
           if (check_arity = opts.fetch(:check_arity, true)) && !block.lambda?
             required_args, optional_args, rest, keyword = _define_roda_method_arg_numbers(block)
 
@@ -117,6 +118,9 @@ def define_roda_method(meth, expected_arity, &block)
                 alias_method meth, meth
                 meth = :"#{meth}_arity"
               elsif required_args > 1
+                if check_arity == :warn
+                  RodaPlugins.warn "Arity mismatch in block passed to define_roda_method. Expected Arity 1, but multiple arguments required for #{block.inspect}"
+                end
                 b = block
                 block = lambda{|r| instance_exec(r, &b)} # Fallback
               end
diff --git a/spec/define_roda_method_spec.rb b/spec/define_roda_method_spec.rb
index f634ead5..5aea3de7 100644
--- a/spec/define_roda_method_spec.rb
+++ b/spec/define_roda_method_spec.rb
@@ -71,6 +71,9 @@
 
     m1 = app.define_roda_method("x", 1){2}
     proc{@scope.send(m1, 1)}.must_raise ArgumentError
+
+    m1 = app.define_roda_method("x", 1){|x, y| [x, y]}
+    proc{@scope.send(m1, 4)}.must_raise ArgumentError
   end
 
   deprecated "should warn if :check_arity :warn app option is used and a block with invalid arity is passed" do
@@ -80,6 +83,9 @@
 
     m1 = app.define_roda_method("x", 1){2}
     @scope.send(m1, 3).must_equal 2
+
+    m1 = app.define_roda_method("x", 1){|x, y| [x, y]}
+    @scope.send(m1, 4).must_equal [4, nil]
   end
 
   [false, true].each do |warn_dynamic_arity|