diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9f2bab5..8a7d3ef 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -104,11 +104,23 @@ macro(UseCompilationWarningAsError)
     if(MSVC)
         # Only enabled in debug because some old versions of VS STL generate
         # warnings when compiled in release configuration.
-        add_compile_options($<$<CONFIG:Debug>:/WX>)
+        if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
+          add_compile_options($<$<CONFIG:Debug>:/WX>)
+        else()
+          set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /WX ")
+        endif()
     elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-        add_compile_options(-Werror)
+        if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
+          add_compile_options(-Werror)
+        else()
+          set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror")
+        endif()
         if(JSONCPP_WITH_STRICT_ISO)
+          if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
             add_compile_options(-pedantic-errors)
+          else()
+            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pedantic-errors")
+          endif()
         endif()
     endif()
 endmacro()
@@ -119,29 +131,57 @@ include_directories( ${jsoncpp_SOURCE_DIR}/include )
 if(MSVC)
     # Only enabled in debug because some old versions of VS STL generate
     # unreachable code warning when compiled in release configuration.
-    add_compile_options($<$<CONFIG:Debug>:/W4>)
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
+      add_compile_options($<$<CONFIG:Debug>:/W4>)
+    else()
+      set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /W4 ")
+    endif()
 endif()
 
 if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     # using regular Clang or AppleClang
-    add_compile_options(-Wall -Wconversion -Wshadow -Werror=conversion -Werror=sign-compare)
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
+      add_compile_options(-Wall -Wconversion -Wshadow -Werror=conversion -Werror=sign-compare)
+    else()
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wconversion -Wshadow -Werror=conversion -Werror=sign-compare")
+    endif()
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     # using GCC
-    add_compile_options(-Wall -Wconversion -Wshadow -Wextra)
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
+      add_compile_options(-Wall -Wconversion -Wshadow -Wextra)
+    else()
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wconversion -Wshadow -Wextra")
+    endif()
     # not yet ready for -Wsign-conversion
 
     if(JSONCPP_WITH_STRICT_ISO)
+      if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
         add_compile_options(-pedantic)
+      else()
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pedantic")
+      endif()
     endif()
     if(JSONCPP_WITH_WARNING_AS_ERROR)
+      if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
         add_compile_options(-Werror=conversion)
+      else()
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror=conversion")
+      endif()
     endif()
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
     # using Intel compiler
-    add_compile_options(-Wall -Wconversion -Wshadow -Wextra -Werror=conversion)
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
+      add_compile_options(-Wall -Wconversion -Wshadow -Wextra -Werror=conversion)
+    else()
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wconversion -Wshadow -Wextra -Werror=conversion")
+    endif()
 
     if(JSONCPP_WITH_STRICT_ISO AND NOT JSONCPP_WITH_WARNING_AS_ERROR)
+      if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
         add_compile_options(-pedantic)
+      else()
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pedantic")
+      endif()
     endif()
 endif()
 
diff --git a/src/jsontestrunner/CMakeLists.txt b/src/jsontestrunner/CMakeLists.txt
index 023a44e..39c6f48 100644
--- a/src/jsontestrunner/CMakeLists.txt
+++ b/src/jsontestrunner/CMakeLists.txt
@@ -5,7 +5,11 @@ add_executable(jsontestrunner_exe
                )
 
 if(BUILD_SHARED_LIBS)
+  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
     add_compile_definitions( JSON_DLL )
+  else()
+    add_definitions( -DJSON_DLL )
+  endif()
 endif()
 target_link_libraries(jsontestrunner_exe jsoncpp_lib)
 
diff --git a/src/lib_json/CMakeLists.txt b/src/lib_json/CMakeLists.txt
index a9bf786..b56788e 100644
--- a/src/lib_json/CMakeLists.txt
+++ b/src/lib_json/CMakeLists.txt
@@ -34,7 +34,11 @@ endif()
 
 if(NOT (HAVE_CLOCALE AND HAVE_LCONV_SIZE AND HAVE_DECIMAL_POINT AND HAVE_LOCALECONV))
     message(WARNING "Locale functionality is not supported")
-    add_compile_definitions(JSONCPP_NO_LOCALE_SUPPORT)
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
+      add_compile_definitions(JSONCPP_NO_LOCALE_SUPPORT)
+    else()
+      add_definitions(-DJSONCPP_NO_LOCALE_SUPPORT)
+    endif()
 endif()
 
 set( JSONCPP_INCLUDE_DIR ../../include )
@@ -66,8 +70,13 @@ else(JSONCPP_WITH_CMAKE_PACKAGE)
     set(INSTALL_EXPORT)
 endif()
 
+
 if(BUILD_SHARED_LIBS)
-    add_compile_definitions( JSON_DLL_BUILD )
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
+      add_compile_definitions( JSON_DLL_BUILD )
+    else()
+      add_definitions( -DJSON_DLL_BUILD )
+    endif()
 endif()
 
 
diff --git a/src/test_lib_json/CMakeLists.txt b/src/test_lib_json/CMakeLists.txt
index abb1813..6e301ec 100644
--- a/src/test_lib_json/CMakeLists.txt
+++ b/src/test_lib_json/CMakeLists.txt
@@ -10,7 +10,11 @@ add_executable( jsoncpp_test
 
 
 if(BUILD_SHARED_LIBS)
+  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12.0)
     add_compile_definitions( JSON_DLL )
+  else()
+    add_definitions( -DJSON_DLL )
+  endif()
 endif()
 target_link_libraries(jsoncpp_test jsoncpp_lib)