diff --git a/README.md b/README.md
index 539c9b1..78f4d58 100644
--- a/README.md
+++ b/README.md
@@ -301,13 +301,12 @@ When building the test suite, Boost 1.54, Qt 5 and Poco are optional dependencie
 ## Supported Parsers
 
 Valijson supports JSON documents loaded using various JSON parser libraries. It has been tested against the following versions of these libraries:
 
  - [boost::property\_tree 1.54](http://www.boost.org/doc/libs/1_54_0/doc/html/boost_propertytree/synopsis.html)
  - [Boost.JSON 1.75](https://www.boost.org/doc/libs/1_75_0/libs/json/doc/html/index.html)
- - [json11 (commit afcc8d0)](https://github.com/dropbox/json11/tree/afcc8d0d82b1ce2df587a7a0637d05ba493bf5e6)
  - [jsoncpp 1.9.4](https://github.com/open-source-parsers/jsoncpp/archive/1.9.4.tar.gz)
  - [nlohmann/json 1.1.0](https://github.com/nlohmann/json/archive/v1.1.0.tar.gz)
  - [rapidjson (commit 48fbd8c)](https://github.com/Tencent/rapidjson/tree/48fbd8cd202ca54031fe799db2ad44ffa8e77c13)
  - [PicoJSON 1.3.0](https://github.com/kazuho/picojson/archive/v1.3.0.tar.gz)
  - [Poco JSON 1.7.8](https://pocoproject.org/docs/Poco.JSON.html)
  - [Qt 5.8](http://doc.qt.io/qt-5/json.html)
diff --git a/tests/test_adapter_comparison.cpp b/tests/test_adapter_comparison.cpp
index f559ef0..8041c9c 100644
--- a/tests/test_adapter_comparison.cpp
+++ b/tests/test_adapter_comparison.cpp
@@ -8,13 +8,11 @@
 
 #include <gtest/gtest.h>
 
-#include <valijson/adapters/json11_adapter.hpp>
 #include <valijson/adapters/jsoncpp_adapter.hpp>
 #include <valijson/adapters/nlohmann_json_adapter.hpp>
 #include <valijson/adapters/picojson_adapter.hpp>
 #include <valijson/adapters/rapidjson_adapter.hpp>
 
-#include <valijson/utils/json11_utils.hpp>
 #include <valijson/utils/jsoncpp_utils.hpp>
 #include <valijson/utils/nlohmann_json_utils.hpp>
 #include <valijson/utils/picojson_utils.hpp>
@@ -333,70 +331,6 @@ TEST_F(TestAdapterComparison, RapidJsonCrtAllocVsRapidJsonCrtAlloc)
             rapidjson::CrtAllocator> > >();
 }
 
-//
-// Json11Adapter vs X
-// ------------------------------------------------------------------------------------------------
-
-TEST_F(TestAdapterComparison, Json11VsJson11)
-{
-    testComparison<
-        valijson::adapters::Json11Adapter,
-        valijson::adapters::Json11Adapter>();
-}
-
-TEST_F(TestAdapterComparison, Json11VsJsonCpp)
-{
-    testComparison<
-        valijson::adapters::Json11Adapter,
-        valijson::adapters::JsonCppAdapter>();
-}
-
-
-TEST_F(TestAdapterComparison, Json11VsRapidJson)
-{
-    testComparison<
-        valijson::adapters::Json11Adapter,
-        valijson::adapters::RapidJsonAdapter>();
-}
-
-TEST_F(TestAdapterComparison, Json11VsRapidJsonCrtAlloc)
-{
-    testComparison<
-        valijson::adapters::Json11Adapter,
-        valijson::adapters::GenericRapidJsonAdapter<
-            rapidjson::GenericValue<rapidjson::UTF8<>,
-            rapidjson::CrtAllocator> > >();
-}
-
-TEST_F(TestAdapterComparison, Json11VsPicoJson)
-{
-    testComparison<
-        valijson::adapters::Json11Adapter,
-        valijson::adapters::PicoJsonAdapter>();
-}
-
-#ifdef VALIJSON_BUILD_BOOST_JSON_ADAPTER
-
-TEST_F(TestAdapterComparison, Json11VsBoostJson)
-{
-    testComparison<
-        valijson::adapters::Json11Adapter,
-        valijson::adapters::BoostJsonAdapter>();
-}
-
-#endif // VALIJSON_BUILD_BOOST_JSON_ADAPTER
-
-#ifdef VALIJSON_BUILD_BOOST_PROPERTY_TREE_ADAPTER
-
-TEST_F(TestAdapterComparison, Json11VsPropertyTree)
-{
-    testComparison<
-        valijson::adapters::Json11Adapter,
-        valijson::adapters::PropertyTreeAdapter>();
-}
-
-#endif // VALIJSON_BUILD_BOOST_PROPERTY_TREE_ADAPTER
-
 //
 // NlohmannJsonAdapter vs X
 // ------------------------------------------------------------------------------------------------
@@ -407,13 +341,6 @@ TEST_F(TestAdapterComparison, NlohmannJsonVsNlohmannJson) {
         valijson::adapters::NlohmannJsonAdapter>();
 }
 
-TEST_F(TestAdapterComparison, NlohmannJsonVsJson11)
-{
-    testComparison<
-            valijson::adapters::NlohmannJsonAdapter,
-            valijson::adapters::Json11Adapter>();
-}
-
 TEST_F(TestAdapterComparison, NlohmannJsonVsJsonCpp)
 {
     testComparison<
@@ -531,13 +458,6 @@ TEST_F(TestAdapterComparison, QtJsonVsPropertyTree)
 
 #endif // VALIJSON_BUILD_BOOST_PROPERTY_TREE_ADAPTER
 
-TEST_F(TestAdapterComparison, QtJsonVsJson11)
-{
-    testComparison<
-            valijson::adapters::QtJsonAdapter,
-            valijson::adapters::Json11Adapter>();
-}
-
 TEST_F(TestAdapterComparison, QtJsonVsNlohmannJson)
 {
     testComparison<
@@ -612,13 +532,6 @@ TEST_F(TestAdapterComparison, PocoJsonVsPropertyTree)
 
 #endif // VALIJSON_BUILD_BOOST_PROPERTY_TREE_ADAPTER
 
-TEST_F(TestAdapterComparison, PocoJsonVsJson11)
-{
-    testComparison<
-            valijson::adapters::PocoJsonAdapter,
-            valijson::adapters::Json11Adapter>();
-}
-
 TEST_F(TestAdapterComparison, PocoJsonVsNlohmannJsonAdapter)
 {
     testComparison<
diff --git a/tests/test_validator.cpp b/tests/test_validator.cpp
index e2bf78e..34b1ecf 100644
--- a/tests/test_validator.cpp
+++ b/tests/test_validator.cpp
@@ -11,12 +11,10 @@
 
 #include <gtest/gtest.h>
 
-#include <valijson/adapters/json11_adapter.hpp>
 #include <valijson/adapters/jsoncpp_adapter.hpp>
 #include <valijson/adapters/rapidjson_adapter.hpp>
 #include <valijson/adapters/picojson_adapter.hpp>
 #include <valijson/adapters/nlohmann_json_adapter.hpp>
-#include <valijson/utils/json11_utils.hpp>
 #include <valijson/utils/jsoncpp_utils.hpp>
 #include <valijson/utils/picojson_utils.hpp>
 #include <valijson/utils/rapidjson_utils.hpp>
@@ -174,7 +172,6 @@ protected:
     void processTestFile(const std::string &testFile,
                          const SchemaParser::Version version)
     {
-        processTestFile<valijson::adapters::Json11Adapter>(testFile, version);
         processTestFile<valijson::adapters::JsonCppAdapter>(testFile, version);
         processTestFile<valijson::adapters::RapidJsonAdapter>(testFile, version);
         processTestFile<valijson::adapters::PicoJsonAdapter>(testFile, version);
diff --git a/tests/test_validator_with_custom_regular_expression_engine.cpp b/tests/test_validator_with_custom_regular_expression_engine.cpp
index 57f09d1..5629f0f 100644
--- a/tests/test_validator_with_custom_regular_expression_engine.cpp
+++ b/tests/test_validator_with_custom_regular_expression_engine.cpp
@@ -7,18 +7,16 @@
 #endif
 
 #include <iostream>
 
 #include <gtest/gtest.h>
 
-#include <valijson/adapters/json11_adapter.hpp>
 #include <valijson/adapters/jsoncpp_adapter.hpp>
 #include <valijson/adapters/rapidjson_adapter.hpp>
 #include <valijson/adapters/picojson_adapter.hpp>
 #include <valijson/adapters/nlohmann_json_adapter.hpp>
-#include <valijson/utils/json11_utils.hpp>
 #include <valijson/utils/jsoncpp_utils.hpp>
 #include <valijson/utils/picojson_utils.hpp>
 #include <valijson/utils/rapidjson_utils.hpp>
 #include <valijson/utils/nlohmann_json_utils.hpp>
 #include <valijson/schema.hpp>
 #include <valijson/schema_parser.hpp>