diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5d5b689..e00db57 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,36 +1,34 @@
 cmake_minimum_required(VERSION 2.8)
 
-# Check if a supported compiler is used and add c++14 flag:
+# Check if a supported compiler is used and add c++11 flag:
 if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
   if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9)
     message(FATAL_ERROR "Need at least gcc 4.9 to compile.")
   endif()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
 elseif(MSVC)
   if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19)
     message(FATAL_ERROR "Visual Studio 2015 or newer is required.")
   endif()
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
+  if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0)
+    message(FATAL_ERROR "Need at least AppleClang 7.0 to compile.")
+  endif()
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
   if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.4)
     message(FATAL_ERROR "Clang below version 3.4 will most likely not work. Please upgrade your compiler.")
   endif()
-
-  if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.6)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++1y")
-  else()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
-  endif()
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
 else() # no GNU, no MSVC, no Clang
   message(WARNING "You are using an unsupported compiler. Compilation has only been tested with MSVC, GCC and Clang.")
 
   include(CheckCXXCompilerFlag)
-  check_cxx_compiler_flag(-std=c++14 HAS_CXX14_FLAG)
-  if(HAS_CXX14_FLAG)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
+  check_cxx_compiler_flag(-std=c++11 HAS_CXX11_FLAG)
+  if(HAS_CXX11_FLAG)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
   else()
-    message(FATAL_ERROR "Your compiler doesn't support the '-std=c++14' flag.")
+    message(FATAL_ERROR "Your compiler doesn't support the '-std=c++11' flag.")
   endif()
 endif()
 
@@ -73,4 +71,4 @@ if(NOT MSVC)
 add_subdirectory(lint)
 add_subdirectory(language/pl0)
 add_subdirectory(language/culebra)
-endif()
\ No newline at end of file
+endif()
diff --git a/lint/peglint.cc b/lint/peglint.cc
index 0a56c87..b590569 100644
--- a/lint/peglint.cc
+++ b/lint/peglint.cc
@@ -91,7 +91,7 @@ int main(int argc, const char** argv)
 
     peg::parser parser;
 
-    parser.log = [&](auto ln, auto col, const auto& msg) {
+    parser.log = [&](size_t ln, size_t col, const string& msg) {
         cerr << syntax_path << ":" << ln << ":" << col << ": " << msg << endl;
     };
 
@@ -114,7 +114,7 @@ int main(int argc, const char** argv)
         source_path = "[commendline]";
     }
 
-    parser.log = [&](auto ln, auto col, const auto& msg) {
+    parser.log = [&](size_t ln, size_t col, const string& msg) {
         cerr << source_path << ":" << ln << ":" << col << ": " << msg << endl;
     };
 
@@ -122,7 +122,13 @@ int main(int argc, const char** argv)
         std::cout << "pos:lev\trule/ope" << std::endl;
         std::cout << "-------\t--------" << std::endl;
         size_t prev_pos = 0;
-        parser.enable_trace([&](auto name, auto s, auto /*n*/, auto& /*sv*/, auto& c, auto& /*dt*/) {
+        parser.enable_trace([&](
+            const char* name,
+            const char* s,
+            size_t /*n*/,
+            const peg::SemanticValues& /*sv*/,
+            const peg::Context& c,
+            const peg::any& /*dt*/) {
             auto pos = static_cast<size_t>(s - c.s);
             auto backtrack = (pos < prev_pos ? "*" : "");
             string indent;