diff --git a/src/serial_posix.c b/src/serial_posix.c
index 7b79ecc..fecc018 100644
--- a/src/serial_posix.c
+++ b/src/serial_posix.c
@@ -181,10 +181,10 @@ dc_serial_open (dc_iostream_t **out, dc_context_t *context, const char *name)
 	dc_status_t status = DC_STATUS_SUCCESS;
 	dc_serial_t *device = NULL;
 
-	if (out == NULL)
+	if (out == NULL || name == NULL)
 		return DC_STATUS_INVALIDARGS;
 
-	INFO (context, "Open: name=%s", name ? name : "");
+	INFO (context, "Open: name=%s", name);
 
 	// Allocate memory.
 	device = (dc_serial_t *) dc_iostream_allocate (context, &dc_serial_vtable);
diff --git a/src/serial_win32.c b/src/serial_win32.c
index fb9940b..4454a74 100644
--- a/src/serial_win32.c
+++ b/src/serial_win32.c
@@ -161,15 +161,15 @@ dc_serial_open (dc_iostream_t **out, dc_context_t *context, const char *name)
 	dc_status_t status = DC_STATUS_SUCCESS;
 	dc_serial_t *device = NULL;
 
-	if (out == NULL)
+	if (out == NULL || name == NULL)
 		return DC_STATUS_INVALIDARGS;
 
-	INFO (context, "Open: name=%s", name ? name : "");
+	INFO (context, "Open: name=%s", name);
 
 	// Build the device name.
 	const char *devname = NULL;
 	char buffer[MAX_PATH] = "\\\\.\\";
-	if (name && strncmp (name, buffer, 4) != 0) {
+	if (strncmp (name, buffer, 4) != 0) {
 		size_t length = strlen (name) + 1;
 		if (length + 4 > sizeof (buffer))
 			return DC_STATUS_NOMEMORY;