diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2018d35..bc506a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,8 +8,13 @@
 
 option(UNSAFE_BUILD "Allow unsafe builds. These builds ARE NOT SECURE." OFF)
 
+string(REGEX MATCH "Clang" CMAKE_COMPILER_IS_CLANG "${CMAKE_C_COMPILER_ID}")
+string(REGEX MATCH "GNU" CMAKE_COMPILER_IS_GNU "${CMAKE_C_COMPILER_ID}")
+string(REGEX MATCH "IAR" CMAKE_COMPILER_IS_IAR "${CMAKE_C_COMPILER_ID}")
+string(REGEX MATCH "MSVC" CMAKE_COMPILER_IS_MSVC "${CMAKE_C_COMPILER_ID}")
+
 # the test suites currently have compile errors with MSVC
-if(MSVC)
+if(CMAKE_COMPILER_IS_MSVC)
     option(ENABLE_TESTING "Build mbed TLS tests." OFF)
 else()
     option(ENABLE_TESTING "Build mbed TLS tests." ON)
@@ -56,9 +61,7 @@
     CACHE STRING "Choose the type of build: None Debug Release Coverage ASan ASanDbg MemSan MemSanDbg Check CheckFull"
     FORCE)
 
-string(REGEX MATCH "Clang" CMAKE_COMPILER_IS_CLANG "${CMAKE_C_COMPILER_ID}")
-
-if(CMAKE_COMPILER_IS_GNUCC)
+if(CMAKE_COMPILER_IS_GNU)
     # some warnings we want are not available with old GCC versions
     # note: starting with CMake 2.8 we could use CMAKE_C_COMPILER_VERSION
     execute_process(COMMAND ${CMAKE_C_COMPILER} -dumpversion
@@ -77,7 +80,7 @@
     set(CMAKE_C_FLAGS_ASANDBG     "-Werror -fsanitize=address -fno-common -O1 -g3 -fno-omit-frame-pointer -fno-optimize-sibling-calls ")
     set(CMAKE_C_FLAGS_CHECK       "-Werror -Os")
     set(CMAKE_C_FLAGS_CHECKFULL   "${CMAKE_C_FLAGS_CHECK} -Wcast-qual")
-endif(CMAKE_COMPILER_IS_GNUCC)
+endif(CMAKE_COMPILER_IS_GNU)
 
 if(CMAKE_COMPILER_IS_CLANG)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -W -Wdeclaration-after-statement -Wwrite-strings -Wpointer-arith -Wimplicit-fallthrough -Wshadow")
@@ -91,16 +94,20 @@
     set(CMAKE_C_FLAGS_CHECK       "-Werror -Os")
 endif(CMAKE_COMPILER_IS_CLANG)
 
-if(MSVC)
+if(CMAKE_COMPILER_IS_IAR)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} --warn_about_c_style_casts --warnings_are_errors -Ohz")
+endif(CMAKE_COMPILER_IS_IAR)
+
+if(CMAKE_COMPILER_IS_MSVC)
     # Strictest warnings, and treat as errors
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /W3")
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /WX")
-endif(MSVC)
+endif(CMAKE_COMPILER_IS_MSVC)
 
 if(CMAKE_BUILD_TYPE STREQUAL "Coverage")
-    if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_CLANG)
+    if(CMAKE_COMPILER_IS_GNU OR CMAKE_COMPILER_IS_CLANG)
         set(CMAKE_SHARED_LINKER_FLAGS "--coverage")
-    endif(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_CLANG)
+    endif(CMAKE_COMPILER_IS_GNU OR CMAKE_COMPILER_IS_CLANG)
 endif(CMAKE_BUILD_TYPE STREQUAL "Coverage")
 
 if(LIB_INSTALL_DIR)