diff --git a/arch/x86_64/src/common/Toolchain.defs b/arch/x86_64/src/common/Toolchain.defs
index 9cc456593e535..fb4b4a93d3a6f 100644
--- a/arch/x86_64/src/common/Toolchain.defs
+++ b/arch/x86_64/src/common/Toolchain.defs
@@ -41,7 +41,9 @@ ifeq ($(CONFIG_DEBUG_SYMBOLS),y)
   ARCHOPTIMIZATION = $(CONFIG_DEBUG_SYMBOLS_LEVEL)
 endif
 
-ifeq ($(CONFIG_DEBUG_CUSTOMOPT),y)
+ifeq ($(CONFIG_DEBUG_NOOPT),y)
+  ARCHOPTIMIZATION += -O0
+else ifeq ($(CONFIG_DEBUG_CUSTOMOPT),y)
   ARCHOPTIMIZATION += $(CONFIG_DEBUG_OPTLEVEL)
 else ifeq ($(CONFIG_DEBUG_FULLOPT),y)
   ARCHOPTIMIZATION += -Os