diff --git a/include/nuttx/fs.h b/include/nuttx/fs.h
index 4623475109..11f6a862a3 100644
--- a/include/nuttx/fs.h
+++ b/include/nuttx/fs.h
@@ -379,7 +379,12 @@ EXTERN int close_blockdriver(FAR struct inode *inode);
 /* Used by the OS to clone stdin, stdout, stderr */
 
 #if CONFIG_NFILE_STREAMS > 0
+
+#ifndef __TCB_DEFINED__
 typedef struct _TCB _TCB;
+#define __TCB_DEFINED__
+#endif
+
 EXTERN FAR struct file_struct *fs_fdopen(int fd, int oflags, FAR _TCB *tcb);
 #endif
 
diff --git a/include/nuttx/sched.h b/include/nuttx/sched.h
index 3fc318a402..7d5fe16bf5 100644
--- a/include/nuttx/sched.h
+++ b/include/nuttx/sched.h
@@ -294,7 +294,15 @@ struct _TCB
 #endif
 
 };
+
+/* Certain other header files may also define this time to avoid circular header
+ * file inclusion issues.
+ */
+
+#ifndef __TCB_DEFINED__
 typedef struct _TCB _TCB;
+#define __TCB_DEFINED__
+#endif
 
 /* This is the callback type used by sched_foreach() */