https://bugs.gentoo.org/840263
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -167,7 +167,6 @@ endmacro()
 macro(jerry_add_compile_warnings)
   foreach(_warning ${ARGV})
     jerry_add_compile_flags(-W${_warning})
-    jerry_add_compile_flags(-Werror=${_warning})
   endforeach()
 endmacro()
 
@@ -212,7 +211,7 @@ if(USING_GCC OR USING_CLANG)
     jerry_add_compile_flags(-fno-builtin)
   endif()
   jerry_add_compile_warnings(all extra format-nonliteral init-self conversion sign-conversion format-security missing-declarations shadow strict-prototypes undef old-style-definition)
-  jerry_add_compile_flags(-Wno-stack-protector -Wno-attributes -Werror)
+  jerry_add_compile_flags(-Wno-stack-protector -Wno-attributes)
 endif()
 
 if(USING_GCC)
--- a/targets/zephyr/Makefile.zephyr
+++ b/targets/zephyr/Makefile.zephyr
@@ -55,9 +55,8 @@ EXT_CFLAGS += -ffunction-sections -fno-inline-functions
 EXT_CFLAGS += $(KBUILD_CFLAGS) $(NOSTDINC_FLAGS) $(subst -I,-isystem,$(ZEPHYRINCLUDE))
 
 EXT_CFLAGS += -Wall -Wno-format-zero-length -Wno-pointer-sign
-EXT_CFLAGS += -Werror=format -Werror=implicit-int -Wno-unused-but-set-variable
+EXT_CFLAGS += -Wformat -Wimplicit-int -Wno-unused-but-set-variable
 EXT_CFLAGS += -Wno-main -Wno-strict-aliasing -Wno-old-style-declaration
-EXT_CFLAGS += -Wno-error=format=
 EXT_CFLAGS += -D_XOPEN_SOURCE=700
 
 EXT_CFLAGS += -Wno-error=conversion