diff --git a/Makefile.include b/Makefile.include
index 5f1aa605a..0759cf726 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -1,6 +1,8 @@
 TOP_DIR       := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
 TOOLCHAIN_DIR ?= $(TOP_DIR)vendor/libopencm3
 
+PYTHON ?= python
+
 ifeq ($(EMULATOR),1)
 CC      = gcc
 LD      = gcc
diff --git a/firmware/Makefile b/firmware/Makefile
index 124f6556b..4ba08837c 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -110,13 +110,13 @@ bootloader.o: ../fastflash/bootloader.bin
 		$< $@
 
 coins_count.h: coins-gen.py coins.json
-	./$< count > $@
+	$(PYTHON) $< count > $@
 
 coins_array.h: coins-gen.py coins.json
-	./$< array > $@
+	$(PYTHON) $< array > $@
 
 nem_mosaics.c nem_mosaics.h: nem_mosaics.py nem_mosaics.json
-	./$<
+	$(PYTHON) $<
 
 clean::
 	rm -f coins_count.h coins_array.h
diff --git a/firmware/nem_mosaics.py b/firmware/nem_mosaics.py
index cb652067b..c2bd6d029 100755
--- a/firmware/nem_mosaics.py
+++ b/firmware/nem_mosaics.py
@@ -9,6 +9,11 @@ from itertools import chain
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), "protob"))
 import types_pb2 as types
 
+try:
+    basestring
+except NameError:
+    basestring = (str, bytes)
+
 HEADER_TEMPLATE = """
 // This file is automatically generated by nem_mosaics.py -- DO NOT EDIT!
 
diff --git a/firmware/protob/Makefile b/firmware/protob/Makefile
index 8dc4c38fd..5a3327f96 100644
--- a/firmware/protob/Makefile
+++ b/firmware/protob/Makefile
@@ -1,7 +1,9 @@
 all: messages.pb.c types.pb.c messages_map.h
 
+PYTHON ?= python
+
 %.pb.c: %.pb %.options
-	../../vendor/nanopb/generator/nanopb_generator.py $< -L '#include "%s"' -T
+	$(PYTHON) ../../vendor/nanopb/generator/nanopb_generator.py $< -L '#include "%s"' -T
 
 %.pb: %.proto
 	protoc -I/usr/include -I. $< -o $@
@@ -10,7 +12,7 @@ all: messages.pb.c types.pb.c messages_map.h
 	protoc -I/usr/include -I. $< --python_out=.
 
 messages_map.h: messages_map.py messages_pb2.py types_pb2.py
-	./$< > $@
+	$(PYTHON) $< > $@
 
 clean:
 	rm -f *.pb *.o *.d *.pb.c *.pb.h *_pb2.py messages_map.h