diff --git a/src/modules/systemlib/bson/tinybson.c b/src/modules/systemlib/bson/tinybson.c
index 5908ace6c7..2378a2d033 100644
--- a/src/modules/systemlib/bson/tinybson.c
+++ b/src/modules/systemlib/bson/tinybson.c
@@ -54,13 +54,24 @@
 #define CODER_CHECK(_c)		do { if (_c->dead) { debug("coder dead"); return -1; }} while(0)
 #define CODER_KILL(_c, _reason)	do { debug("killed: %s", _reason); _c->dead = true; return -1; } while(0)
 
+#ifdef __PX4_QURT
+#define BSON_READ  px4_read
+#define BSON_WRITE px4_write
+#define BSON_FSYNC px4_fsync
+#else
+#define BSON_READ  read
+#define BSON_WRITE write
+#define BSON_FSYNC fsync
+#endif
+
 static int
 read_x(bson_decoder_t decoder, void *p, size_t s)
 {
 	CODER_CHECK(decoder);
 
-	if (decoder->fd > -1)
-		return (px4_read(decoder->fd, p, s) == (int)s) ? 0 : -1;
+	if (decoder->fd > -1) {
+		return (BSON_READ(decoder->fd, p, s) == (int)s) ? 0 : -1;
+	}
 
 	if (decoder->buf != NULL) {
 		/* staged operations to avoid integer overflow for corrupt data */
@@ -302,7 +313,7 @@ write_x(bson_encoder_t encoder, const void *p, size_t s)
 	CODER_CHECK(encoder);
 
 	if (encoder->fd > -1)
-		return (px4_write(encoder->fd, p, s) == (int)s) ? 0 : -1;
+		return (BSON_WRITE(encoder->fd, p, s) == (int)s) ? 0 : -1;
 
 	/* do we need to extend the buffer? */
 	while ((encoder->bufpos + s) > encoder->bufsize) {
@@ -409,7 +420,7 @@ bson_encoder_fini(bson_encoder_t encoder)
 	}
 
 	/* sync file */
-	px4_fsync(encoder->fd);
+	BSON_FSYNC(encoder->fd);
 
 	return 0;
 }
diff --git a/src/modules/systemlib/param/param.c b/src/modules/systemlib/param/param.c
index ca0b7296c3..09e9e88870 100644
--- a/src/modules/systemlib/param/param.c
+++ b/src/modules/systemlib/param/param.c
@@ -70,6 +70,14 @@
 # define debug(fmt, args...)		do { } while(0)
 #endif
 
+#ifdef __PX4_QURT
+#define PARAM_OPEN	px4_open
+#define PARAM_CLOSE	px4_close
+#else
+#define PARAM_OPEN	open
+#define PARAM_CLOSE	close
+#endif
+
 /**
  * Array of static parameter info.
  */
@@ -707,7 +715,7 @@ param_save_default(void)
 	const char *filename = param_get_default_file();
 
 	/* write parameters to temp file */
-	fd = px4_open(filename, O_WRONLY | O_CREAT, 0x777);
+	fd = PARAM_OPEN(filename, O_WRONLY | O_CREAT, 0x777);
 
 	if (fd < 0) {
 		warn("failed to open param file: %s", filename);
@@ -720,7 +728,7 @@ param_save_default(void)
 		warnx("failed to write parameters to file: %s", filename);
 	}
 
-	px4_close(fd);
+	PARAM_CLOSE(fd);
 
 	return res;
 }
@@ -732,7 +740,7 @@ int
 param_load_default(void)
 {
 	warnx("param_load_default\n");
-	int fd_load = px4_open(param_get_default_file(), O_RDONLY);
+	int fd_load = PARAM_OPEN(param_get_default_file(), O_RDONLY);
 
 	if (fd_load < 0) {
 		/* no parameter file is OK, otherwise this is an error */
@@ -745,7 +753,7 @@ param_load_default(void)
 	}
 
 	int result = param_load(fd_load);
-	px4_close(fd_load);
+	PARAM_CLOSE(fd_load);
 
 	if (result != 0) {
 		warn("error reading parameters from '%s'", param_get_default_file());
diff --git a/unittests/CMakeLists.txt b/unittests/CMakeLists.txt
index 96c2f995f7..ae87cfca7a 100644
--- a/unittests/CMakeLists.txt
+++ b/unittests/CMakeLists.txt
@@ -33,6 +33,7 @@ add_definitions(-Dmain_t=int)
 add_definitions(-DERROR=-1)
 add_definitions(-DOK=0)
 add_definitions(-D_UNIT_TEST=)
+add_definitions(-D__PX4_POSIX)
 add_definitions(-D__PX4_LINUX)
 
 # check