diff --git a/src/lib/cdev/posix/cdev_platform.cpp b/src/lib/cdev/posix/cdev_platform.cpp
index 30b59279b2..16a956b673 100644
--- a/src/lib/cdev/posix/cdev_platform.cpp
+++ b/src/lib/cdev/posix/cdev_platform.cpp
@@ -62,9 +62,8 @@ private:
 	px4_dev_t() = default;
 };
 
-static px4_dev_t *devmap[256] {};
-
-#define PX4_MAX_FD 256
+#define PX4_MAX_FD 512
+static px4_dev_t *devmap[PX4_MAX_FD] {};
 static cdev::file_t filemap[PX4_MAX_FD] {};
 
 class VFile : public cdev::CDev