diff --git a/fifo.c b/fifo.c
index f7675f2..e33a4e2 100644
--- a/fifo.c
+++ b/fifo.c
@@ -140,11 +140,13 @@ struct mag_buf *fifo_acquire(uint32_t timeout_ms)
         }
 
         // No free buffers, wait for one
-        if (pthread_cond_timedwait(&fifo_free_cond, &fifo_mutex, &deadline) < 0) {
-            if (errno != ETIMEDOUT)
-                return NULL; // unexpected error, mutex no longer held!
+        int err = pthread_cond_timedwait(&fifo_free_cond, &fifo_mutex, &deadline);
+        if (err) {
+            if (err != ETIMEDOUT) {
+                fprintf(stderr, "fifo_acquire: pthread_cond_timedwait unexpectedly returned %s\n", strerror(err));
+            }
 
-            goto done; // timed out
+            goto done; // done waiting
         }
     }
 
@@ -219,11 +221,13 @@ struct mag_buf *fifo_dequeue(uint32_t timeout_ms)
         }
 
         // No data pending, wait for some
-        if (pthread_cond_timedwait(&fifo_notempty_cond, &fifo_mutex, &deadline) < 0) {
-            if (errno != ETIMEDOUT)
-                return NULL; // unexpected error, mutex no longer held!
+        int err = pthread_cond_timedwait(&fifo_notempty_cond, &fifo_mutex, &deadline);
+        if (err) {
+            if (err != ETIMEDOUT) {
+                fprintf(stderr, "fifo_dequeue: pthread_cond_timedwait unexpectedly returned %s\n", strerror(err));
+            }
 
-            goto done; // timed out
+            goto done; // done waiting
         }
     }