diff --git a/lib/rscons/cache.rb b/lib/rscons/cache.rb
index 5d499e7..1b36eac 100644
--- a/lib/rscons/cache.rb
+++ b/lib/rscons/cache.rb
@@ -100,7 +100,6 @@ module Rscons
     # @return [void]
     def write
       @cache["version"] = VERSION
-      validate_json_object(@cache)
       File.open(CACHE_FILE, "w") do |fh|
         fh.puts(JSON.dump(@cache))
       end
@@ -384,20 +383,5 @@ module Rscons
       @lookup_checksums[file] = Digest::MD5.hexdigest(File.read(file, mode: "rb")) rescue ""
     end
 
-    # Validate that an object is one of a known set of values that can be
-    # serialized properly with JSON.
-    #
-    # @param o [Object]
-    #   Object to validate.
-    def validate_json_object(o)
-      if o.is_a?(Array)
-        o.each {|v| validate_json_object(v)}
-      elsif o.is_a?(Hash)
-        o.each {|*kv| validate_json_object(kv)}
-      elsif [NilClass, TrueClass, FalseClass, String].none? {|c| o.is_a?(c)}
-        raise "Unexpected cache value for serialization: #{o.inspect}"
-      end
-    end
-
   end
 end
diff --git a/spec/rscons/cache_spec.rb b/spec/rscons/cache_spec.rb
index 2005ff4..3972bfc 100644
--- a/spec/rscons/cache_spec.rb
+++ b/spec/rscons/cache_spec.rb
@@ -65,12 +65,5 @@ module Rscons
         expect(build_from({}).send(:calculate_checksum, "fname")).to eq "the_checksum"
       end
     end
-
-    describe "#validate_json_object" do
-      it "raises an error when an unexpected object is passed" do
-        cache = build_from({})
-        expect {cache.__send__(:validate_json_object, :symbol)}.to raise_error /Unexpected cache value/
-      end
-    end
   end
 end