diff --git a/examples/natmod/btree/Makefile b/examples/natmod/btree/Makefile
index d795102b4a..218ec15a2a 100644
--- a/examples/natmod/btree/Makefile
+++ b/examples/natmod/btree/Makefile
@@ -11,9 +11,10 @@ SRC = btree_c.c btree_py.py
 ARCH = x64
 
 BTREE_DIR = $(MPY_DIR)/lib/berkeley-db-1.xx
-BTREE_DEFS = -D__DBINTERFACE_PRIVATE=1 -Dmpool_error="(void)" -Dabort=abort_ "-Dvirt_fd_t=void*" $(BTREE_DEFS_EXTRA)
-CFLAGS += -I$(BTREE_DIR)/PORT/include
-CFLAGS += -Wno-old-style-definition -Wno-sign-compare -Wno-unused-parameter $(BTREE_DEFS)
+BERKELEY_DB_CONFIG_FILE ?= \"extmod/berkeley-db/berkeley_db_config_port.h\"
+CFLAGS += -I$(BTREE_DIR)/include
+CFLAGS += -DBERKELEY_DB_CONFIG_FILE=$(BERKELEY_DB_CONFIG_FILE)
+CFLAGS += -Wno-old-style-definition -Wno-sign-compare -Wno-unused-parameter
 
 SRC += $(addprefix $(realpath $(BTREE_DIR))/,\
 	btree/bt_close.c \
diff --git a/examples/natmod/btree/btree_c.c b/examples/natmod/btree/btree_c.c
index 3c60e41b2d..bbf51c731f 100644
--- a/examples/natmod/btree/btree_c.c
+++ b/examples/natmod/btree/btree_c.c
@@ -39,6 +39,10 @@ void abort_(void) {
     nlr_raise(mp_obj_new_exception(mp_load_global(MP_QSTR_RuntimeError)));
 }
 
+int puts(const char *s) {
+    return mp_printf(&mp_plat_print, "%s\n", s);
+}
+
 int native_errno;
 #if defined(__linux__)
 int *__errno_location (void)
diff --git a/extmod/berkeley-db/berkeley_db_config_port.h b/extmod/berkeley-db/berkeley_db_config_port.h
new file mode 100644
index 0000000000..41e4acd81e
--- /dev/null
+++ b/extmod/berkeley-db/berkeley_db_config_port.h
@@ -0,0 +1,16 @@
+// Berkeley-db configuration.
+
+#define __DBINTERFACE_PRIVATE 1
+#define mpool_error printf
+#define abort abort_
+#define virt_fd_t void*
+
+#ifdef MICROPY_BERKELEY_DB_DEFPSIZE
+#define DEFPSIZE MICROPY_BERKELEY_DB_DEFPSIZE
+#endif
+
+#ifdef MICROPY_BERKELEY_DB_MINCACHE
+#define MINCACHE MICROPY_BERKELEY_DB_MINCACHE
+#endif
+
+__attribute__((noreturn)) void abort_(void);
diff --git a/extmod/extmod.cmake b/extmod/extmod.cmake
index 957580d15d..60f1a23ad6 100644
--- a/extmod/extmod.cmake
+++ b/extmod/extmod.cmake
@@ -132,27 +132,27 @@ if(MICROPY_PY_BTREE)
         )
 
         target_include_directories(micropy_extmod_btree PRIVATE
-            ${MICROPY_LIB_BERKELEY_DIR}/PORT/include
+            ${MICROPY_LIB_BERKELEY_DIR}/include
         )
 
+        if(NOT BERKELEY_DB_CONFIG_FILE)
+            set(BERKELEY_DB_CONFIG_FILE "${MICROPY_DIR}/extmod/berkeley-db/berkeley_db_config_port.h")
+        endif()
+
         target_compile_definitions(micropy_extmod_btree PRIVATE
-            __DBINTERFACE_PRIVATE=1
-            mpool_error=printf
-            abort=abort_
-            "virt_fd_t=void*"
+            BERKELEY_DB_CONFIG_FILE="${BERKELEY_DB_CONFIG_FILE}"
         )
 
         # The include directories and compile definitions below are needed to build
         # modbtree.c and should be added to the main MicroPython target.
 
         list(APPEND MICROPY_INC_CORE
-            "${MICROPY_LIB_BERKELEY_DIR}/PORT/include"
+            "${MICROPY_LIB_BERKELEY_DIR}/include"
         )
 
         list(APPEND MICROPY_DEF_CORE
             MICROPY_PY_BTREE=1
-            __DBINTERFACE_PRIVATE=1
-            "virt_fd_t=void*"
+            BERKELEY_DB_CONFIG_FILE="${BERKELEY_DB_CONFIG_FILE}"
         )
 
         list(APPEND MICROPY_SOURCE_EXTMOD
diff --git a/extmod/extmod.mk b/extmod/extmod.mk
index bf686fbbb4..f7c6f9988e 100644
--- a/extmod/extmod.mk
+++ b/extmod/extmod.mk
@@ -381,8 +381,10 @@ endif
 
 ifeq ($(MICROPY_PY_BTREE),1)
 BTREE_DIR = lib/berkeley-db-1.xx
-BTREE_DEFS = -D__DBINTERFACE_PRIVATE=1 -Dmpool_error=printf -Dabort=abort_ "-Dvirt_fd_t=void*" $(BTREE_DEFS_EXTRA)
-INC += -I$(TOP)/$(BTREE_DIR)/PORT/include
+BERKELEY_DB_CONFIG_FILE ?= \"extmod/berkeley-db/berkeley_db_config_port.h\"
+CFLAGS_EXTMOD += -DBERKELEY_DB_CONFIG_FILE=$(BERKELEY_DB_CONFIG_FILE)
+CFLAGS_EXTMOD += $(BTREE_DEFS_EXTRA)
+INC += -I$(TOP)/$(BTREE_DIR)/include
 SRC_THIRDPARTY_C += $(addprefix $(BTREE_DIR)/,\
 	btree/bt_close.c \
 	btree/bt_conv.c \
@@ -401,9 +403,7 @@ SRC_THIRDPARTY_C += $(addprefix $(BTREE_DIR)/,\
 	)
 CFLAGS_EXTMOD += -DMICROPY_PY_BTREE=1
 # we need to suppress certain warnings to get berkeley-db to compile cleanly
-# and we have separate BTREE_DEFS so the definitions don't interfere with other source code
-$(BUILD)/$(BTREE_DIR)/%.o: CFLAGS += -Wno-old-style-definition -Wno-sign-compare -Wno-unused-parameter -Wno-deprecated-non-prototype -Wno-unknown-warning-option $(BTREE_DEFS)
-$(BUILD)/extmod/modbtree.o: CFLAGS += $(BTREE_DEFS)
+$(BUILD)/$(BTREE_DIR)/%.o: CFLAGS += -Wno-old-style-definition -Wno-sign-compare -Wno-unused-parameter -Wno-deprecated-non-prototype -Wno-unknown-warning-option
 endif
 
 ################################################################################
diff --git a/extmod/modbtree.c b/extmod/modbtree.c
index f8c38e0ad4..55c13ac911 100644
--- a/extmod/modbtree.c
+++ b/extmod/modbtree.c
@@ -57,8 +57,8 @@
 #undef CIRCLEQ_INSERT_TAIL
 #undef CIRCLEQ_REMOVE
 
-#include <db.h>
-#include <../../btree/btree.h>
+#include "berkeley-db/db.h"
+#include "berkeley-db/btree.h"
 
 typedef struct _mp_obj_btree_t {
     mp_obj_base_t base;
diff --git a/ports/esp8266/Makefile b/ports/esp8266/Makefile
index 32eb39a203..8af7aba0aa 100644
--- a/ports/esp8266/Makefile
+++ b/ports/esp8266/Makefile
@@ -38,7 +38,7 @@ MICROPY_ROM_TEXT_COMPRESSION ?= 1
 MICROPY_PY_SSL = 1
 MICROPY_SSL_AXTLS = 1
 AXTLS_DEFS_EXTRA = -Dabort=abort_ -DRT_MAX_PLAIN_LENGTH=1024 -DRT_EXTRA=4096
-BTREE_DEFS_EXTRA = -DDEFPSIZE=1024 -DMINCACHE=3
+BTREE_DEFS_EXTRA = -DMICROPY_BERKELEY_DB_DEFPSIZE=1024 -DMICROPY_BERKELEY_DB_MINCACHE=3
 
 FROZEN_MANIFEST ?= boards/manifest.py