diff --git a/lib/mongoid/criteria/queryable/extensions/numeric.rb b/lib/mongoid/criteria/queryable/extensions/numeric.rb
index b4b63522df..3c6a3f2bf6 100644
--- a/lib/mongoid/criteria/queryable/extensions/numeric.rb
+++ b/lib/mongoid/criteria/queryable/extensions/numeric.rb
@@ -33,20 +33,6 @@ def __evolve_time__
 
           module ClassMethods
 
-            # Get the object as a numeric.
-            #
-            # @api private
-            #
-            # @example Get the object as numeric.
-            #   Object.__numeric__("1.442")
-            #
-            # @param [ Object ] object The object to convert.
-            #
-            # @return [ Object ] The converted number.
-            def __numeric__(object)
-              object.to_s.match?(/\A[-+]?[0-9]*[0-9.]0*\z/) ? object.to_i : Float(object)
-            end
-
             # Evolve the object to an integer.
             #
             # @example Evolve to integers.
@@ -57,7 +43,9 @@ def __numeric__(object)
             # @return [ Integer ] The evolved object.
             def evolve(object)
               __evolve__(object) do |obj|
-                __numeric__(obj) rescue obj
+                obj.to_s.match?(/\A[-+]?[0-9]*[0-9.]0*\z/) ? obj.to_i : Float(obj)
+              rescue
+                obj
               end
             end
           end
diff --git a/spec/mongoid/criteria/queryable/extensions/numeric_spec.rb b/spec/mongoid/criteria/queryable/extensions/numeric_spec.rb
index 4fca979182..1da51ab3fd 100644
--- a/spec/mongoid/criteria/queryable/extensions/numeric_spec.rb
+++ b/spec/mongoid/criteria/queryable/extensions/numeric_spec.rb
@@ -7,12 +7,12 @@
 
   let(:host) do
     Class.new do
-      include Mongoid::Criteria::Queryable::Extensions::Numeric::ClassMethods
-    end.new
+      extend Mongoid::Criteria::Queryable::Extensions::Numeric::ClassMethods
+    end
   end
 
-  describe "#__numeric__" do
-    let(:actual) { host.__numeric__(str) }
+  describe ".evolve" do
+    let(:actual) { host.evolve(str) }
 
     context "when the string is a whole number" do
       let(:str) { '123' }
@@ -80,40 +80,40 @@
     context "when the string is non-numeric" do
       let(:str) { 'foo' }
 
-      it "raises ArgumentError" do
-        expect { actual }.to raise_error(ArgumentError)
+      it "returns the string" do
+        expect(actual).to eq(str)
       end
     end
 
     context "when the string is non-numeric with leading dot" do
       let(:str) { '.foo' }
 
-      it "raises ArgumentError" do
-        expect { actual }.to raise_error(ArgumentError)
+      it "returns the string" do
+        expect(actual).to eq(str)
       end
     end
 
     context "when the string is non-numeric with trailing dot" do
       let(:str) { 'foo.' }
 
-      it "raises ArgumentError" do
-        expect { actual }.to raise_error(ArgumentError)
+      it "returns the string" do
+        expect(actual).to eq(str)
       end
     end
 
     context "when the string is non-numeric with trailing dot and zeroes" do
       let(:str) { 'foo.000' }
 
-      it "raises ArgumentError" do
-        expect { actual }.to raise_error(ArgumentError)
+      it "returns the string" do
+        expect(actual).to eq(str)
       end
     end
 
     context "when the string is empty" do
       let(:str) { '' }
 
-      it "raises ArgumentError" do
-        expect { actual }.to raise_error(ArgumentError)
+      it "returns the string" do
+        expect(actual).to eq(str)
       end
     end
   end