diff --git a/unix/Makefile b/unix/Makefile
index 830f30742469fd3f8d885de93dabe428ce52faa2..837ddf2b78c55d612de1fc5215c54aae1a32b154 100644
--- a/unix/Makefile
+++ b/unix/Makefile
@@ -211,7 +211,7 @@ fast:
 # build a minimal interpreter
 minimal:
 	$(MAKE) COPT="-Os -DNDEBUG" CFLAGS_EXTRA='-DMP_CONFIGFILE="<mpconfigport_minimal.h>"' \
-	    BUILD=build-minimal PROG=micropython_minimal FROZEN_DIR= \
+	    BUILD=build-minimal PROG=micropython_minimal FROZEN_DIR= FROZEN_MPY_DIR= \
 	    MICROPY_PY_BTREE=0 MICROPY_PY_FFI=0 MICROPY_PY_SOCKET=0 MICROPY_PY_THREAD=0 \
 	    MICROPY_PY_TERMIOS=0 MICROPY_PY_USSL=0 \
 	    MICROPY_USE_READLINE=0