diff --git a/make_helpers/plat_helpers.mk b/make_helpers/plat_helpers.mk
index a7ae9a2..bc02a20 100644
--- a/make_helpers/plat_helpers.mk
+++ b/make_helpers/plat_helpers.mk
@@ -11,6 +11,7 @@
 ifndef PLAT_HELPERS_MK
     PLAT_HELPERS_MK := $(lastword $(MAKEFILE_LIST))
 
+    PLAT:= ${DEFAULT_PLAT}
     ifeq (${PLAT},)
         $(error "Error: Unknown platform. Please use PLAT=<platform name> to specify the platform")
     endif
@@ -18,15 +19,18 @@
     # TF_PLATFORM_ROOT can be overridden for when building tools directly
     TF_PLATFORM_ROOT               ?= plat/
     PLAT_MAKEFILE               := platform.mk
+    PLAT_DEFAULTS_MAKEFILE      := platform_defaults.mk
 
     # Generate the platforms list by recursively searching for all directories
     # under /plat containing a PLAT_MAKEFILE. Append each platform with a `|`
     # char and strip out the final '|'.
     ALL_PLATFORM_MK_FILES       := $(call rwildcard,${TF_PLATFORM_ROOT},${PLAT_MAKEFILE})
+    ALL_PLATFORM_MK_DEF_FILES   := $(call rwildcard,${TF_PLATFORM_ROOT},${PLAT_DEFAULTS_MAKEFILE})
     ALL_PLATFORM_DIRS           := $(patsubst %/,%,$(dir ${ALL_PLATFORM_MK_FILES}))
     ALL_PLATFORMS               := $(sort $(notdir ${ALL_PLATFORM_DIRS}))
 
     PLAT_MAKEFILE_FULL          := $(filter %/${PLAT}/${PLAT_MAKEFILE},${ALL_PLATFORM_MK_FILES})
+    PLAT_DEFAULTS_MAKEFILE_FULL := $(filter %/${PLAT}/${PLAT_DEFAULTS_MAKEFILE},${ALL_PLATFORM_MK_DEF_FILES})
     PLATFORM_LIST               := $(subst ${space},|,${ALL_PLATFORMS})
     ifeq ($(PLAT_MAKEFILE_FULL),)
         $(error "Error: Invalid platform. The following platforms are available: ${PLATFORM_LIST}")