diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9431ceac4f..f6421cbf6b 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,7 +20,7 @@ project (Jerry C ASM)
  string(TOUPPER "${PLATFORM}" PLATFORM)
 
 # Compiler configuration
- if(NOT ("${PLATFORM}" STREQUAL "DARWIN"))
+ if(NOT (("${PLATFORM}" STREQUAL "DARWIN") OR ("${PLATFORM}" STREQUAL "EXTERNAL")))
   if(NOT CMAKE_COMPILER_IS_GNUCC)
    message(FATAL_ERROR "gcc compiler is required")
   endif()
diff --git a/build/configs/toolchain_external.cmake b/build/configs/toolchain_external.cmake
index 30f004d71c..f1e25b2be0 100644
--- a/build/configs/toolchain_external.cmake
+++ b/build/configs/toolchain_external.cmake
@@ -17,4 +17,4 @@ include(CMakeForceCompiler)
 set(CMAKE_SYSTEM_NAME EXTERNAL)
 set(CMAKE_SYSTEM_PROCESSOR "${EXTERNAL_CMAKE_SYSTEM_PROCESSOR}")
 
-CMAKE_FORCE_C_COMPILER(${EXTERNAL_CMAKE_C_COMPILER} GNU)
+CMAKE_FORCE_C_COMPILER(${EXTERNAL_CMAKE_C_COMPILER} ${EXTERNAL_CMAKE_C_COMPILER_ID})
diff --git a/targets/esp8266/Makefile.esp8266 b/targets/esp8266/Makefile.esp8266
index 7abf4adfe9..4edc315d41 100644
--- a/targets/esp8266/Makefile.esp8266
+++ b/targets/esp8266/Makefile.esp8266
@@ -64,6 +64,7 @@ jerry:
 	 -DCMAKE_TOOLCHAIN_FILE=build/configs/toolchain_external.cmake \
 	 -DEXTERNAL_CMAKE_SYSTEM_PROCESSOR=xtensia-lx106 \
 	 -DEXTERNAL_CMAKE_C_COMPILER=xtensa-lx106-elf-gcc \
+	 -DEXTERNAL_CMAKE_C_COMPILER_ID=GNU \
 	 -DEXTERNAL_BUILD_ENTRY_FILE="$(JERRY_BUILD_FILES)" \
 	 -DEXTERNAL_COMPILE_FLAGS="$(ESP_CFLAGS)" \
 	 -DEXTERNAL_LIBC_INTERFACE="$(ESP_INC)" \
diff --git a/targets/mbedk64f/Makefile.mbedk64f b/targets/mbedk64f/Makefile.mbedk64f
index 45345339ed..e17da3a549 100644
--- a/targets/mbedk64f/Makefile.mbedk64f
+++ b/targets/mbedk64f/Makefile.mbedk64f
@@ -44,6 +44,7 @@ jerry:
 	 -DUSE_COMPILER_DEFAULT_LIBC=YES \
 	 -DEXTERNAL_CMAKE_SYSTEM_PROCESSOR=arm7-m \
 	 -DEXTERNAL_CMAKE_C_COMPILER=arm-none-eabi-gcc \
+	 -DEXTERNAL_CMAKE_C_COMPILER_ID=GNU \
 	 -DEXTERNAL_COMPILE_FLAGS="$(EXT_CFLAGS)" \
 	 -DEXTERNAL_MEM_HEAP_SIZE_KB=$(JERRYHEAP)
 
diff --git a/targets/nuttx-stm32f4/Makefile.nuttx b/targets/nuttx-stm32f4/Makefile.nuttx
index b9469b9ae6..966c399bdd 100644
--- a/targets/nuttx-stm32f4/Makefile.nuttx
+++ b/targets/nuttx-stm32f4/Makefile.nuttx
@@ -42,6 +42,7 @@ all:
 	 -DCMAKE_TOOLCHAIN_FILE=build/configs/toolchain_external.cmake \
 	 -DEXTERNAL_CMAKE_SYSTEM_PROCESSOR=armv7l-hf \
 	 -DEXTERNAL_CMAKE_C_COMPILER=arm-none-eabi-gcc \
+	 -DEXTERNAL_CMAKE_C_COMPILER_ID=GNU \
 	 -DEXTERNAL_BUILD_ENTRY_FILE=./targets/nuttx-stm32f4/main-nuttx.c \
 	 -DEXTERNAL_COMPILE_FLAGS="$(EXT_CFLAGS)" \
 	 -DEXTERNAL_LIBC_INTERFACE=$(NUTTXINC) \