diff --git a/extmod/extmod.mk b/extmod/extmod.mk
index c087e13cbd..08138ead56 100644
--- a/extmod/extmod.mk
+++ b/extmod/extmod.mk
@@ -131,7 +131,9 @@ SRC_THIRDPARTY_C += $(addprefix $(AXTLS_DIR)/,\
 	)
 else ifeq ($(MICROPY_SSL_MBEDTLS),1)
 MBEDTLS_DIR = lib/mbedtls
+MBEDTLS_CONFIG_FILE ?= \"mbedtls/mbedtls_config.h\"
 GIT_SUBMODULES += $(MBEDTLS_DIR)
+CFLAGS_EXTMOD += -DMBEDTLS_CONFIG_FILE=$(MBEDTLS_CONFIG_FILE)
 CFLAGS_EXTMOD += -DMICROPY_SSL_MBEDTLS=1 -I$(TOP)/$(MBEDTLS_DIR)/include
 SRC_THIRDPARTY_C += lib/mbedtls_errors/mp_mbedtls_errors.c
 SRC_THIRDPARTY_C += $(addprefix $(MBEDTLS_DIR)/library/,\
diff --git a/ports/mimxrt/Makefile b/ports/mimxrt/Makefile
index ae8cf16f16..c65e2a433c 100644
--- a/ports/mimxrt/Makefile
+++ b/ports/mimxrt/Makefile
@@ -345,8 +345,7 @@ endif
 # All settings for Ethernet support are controller by the value of MICROPY_PY_LWIP
 ifeq ($(MICROPY_PY_LWIP),1)
 CFLAGS += \
-	-DFSL_FEATURE_PHYKSZ8081_USE_RMII50M_MODE=1 \
-	-DMBEDTLS_CONFIG_FILE='"mbedtls/mbedtls_config.h"'
+	-DFSL_FEATURE_PHYKSZ8081_USE_RMII50M_MODE=1
 endif
 
 CFLAGS += $(CFLAGS_EXTRA)
diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index 141aadcf38..07d366bfea 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -474,8 +474,6 @@ USBDEV_SRC_C += $(addprefix $(USBDEV_DIR)/,\
 	)
 
 ifeq ($(MICROPY_SSL_MBEDTLS),1)
-MBEDTLS_CONFIG_FILE ?= '"mbedtls/mbedtls_config.h"'
-CFLAGS += -DMBEDTLS_CONFIG_FILE=$(MBEDTLS_CONFIG_FILE)
 LIB_SRC_C += mbedtls/mbedtls_port.c
 endif
 
diff --git a/ports/unix/Makefile b/ports/unix/Makefile
index 360cdd6f8c..cd18a6ed1e 100644
--- a/ports/unix/Makefile
+++ b/ports/unix/Makefile
@@ -134,9 +134,6 @@ endif
 ifeq ($(MICROPY_PY_USSL),1)
 ifeq ($(MICROPY_SSL_AXTLS),1)
 
-endif
-ifeq ($(MICROPY_SSL_MBEDTLS),1)
-CFLAGS += -DMBEDTLS_CONFIG_FILE='"mbedtls/mbedtls_config.h"'
 endif
 endif