diff --git a/platform/source/mbed_retarget.cpp b/platform/source/mbed_retarget.cpp
index 6679d87219..61adeeb0f9 100644
--- a/platform/source/mbed_retarget.cpp
+++ b/platform/source/mbed_retarget.cpp
@@ -443,7 +443,7 @@ std::FILE *fdopen(FileHandle *fh, const char *mode)
 {
     // First reserve the integer file descriptor
     int fd = bind_to_fd(fh);
-    if (!fd) {
+    if (fd < 0) {
         return NULL;
     }
     // Then bind that to the C stream. If successful, C library
@@ -825,6 +825,7 @@ int _lseek(FILEHANDLE fh, int offset, int whence)
 
     off_t off = lseek(fh, offset, whence);
     // Assuming INT_MAX = LONG_MAX, so we don't care about prototype difference
+    // coverity[result_independent_of_operands]
     if (off > INT_MAX) {
         // Be cautious in case off_t is 64-bit
         errno = EOVERFLOW;
diff --git a/rtos/source/TARGET_CORTEX/rtx4/cmsis_os1.c b/rtos/source/TARGET_CORTEX/rtx4/cmsis_os1.c
index a68eb0a1d8..ce0ca3f7be 100644
--- a/rtos/source/TARGET_CORTEX/rtx4/cmsis_os1.c
+++ b/rtos/source/TARGET_CORTEX/rtx4/cmsis_os1.c
@@ -267,6 +267,7 @@ osMailQId osMailCreate (const osMailQDef_t *queue_def, osThreadId thread_id) {
   }
 
   ptr->mp_id = osMemoryPoolNew  (queue_def->queue_sz, queue_def->item_sz, &queue_def->mp_attr);
+  // coverity[suspicious_sizeof]
   ptr->mq_id = osMessageQueueNew(queue_def->queue_sz, sizeof(void *), &queue_def->mq_attr);
   if ((ptr->mp_id == NULL) || (ptr->mq_id == NULL)) {
     if (ptr->mp_id != NULL) {