diff --git a/Source/include/croutine.h b/Source/include/croutine.h
index 9b55e079d8..149bd7e1f0 100644
--- a/Source/include/croutine.h
+++ b/Source/include/croutine.h
@@ -46,6 +46,14 @@
 	http://www.OpenRTOS.com - Commercial support, development, porting, 
 	licensing and training services.
 */
+
+#ifndef INC_FREERTOS_H
+	#error #error "#include FreeRTOS.h" must appear in source files before "#include croutine.h"
+#endif
+
+
+
+
 #ifndef CO_ROUTINE_H
 #define CO_ROUTINE_H
 
diff --git a/Source/include/queue.h b/Source/include/queue.h
index 10b7f418c1..2d3962f562 100644
--- a/Source/include/queue.h
+++ b/Source/include/queue.h
@@ -47,6 +47,13 @@
 	licensing and training services.
 */
 
+#ifndef INC_FREERTOS_H
+	#error "#include FreeRTOS.h" must appear in source files before "#include queue.h"
+#endif
+
+
+
+
 #ifndef QUEUE_H
 #define QUEUE_H
 
diff --git a/Source/include/semphr.h b/Source/include/semphr.h
index c6b1d02ac8..786d017203 100644
--- a/Source/include/semphr.h
+++ b/Source/include/semphr.h
@@ -47,6 +47,10 @@
 	licensing and training services.
 */
 
+#ifndef INC_FREERTOS_H
+	#error "#include FreeRTOS.h" must appear in source files before "#include semphr.h"
+#endif
+
 #ifndef SEMAPHORE_H
 #define SEMAPHORE_H
 
diff --git a/Source/include/task.h b/Source/include/task.h
index 808fd95ee6..60193cfb73 100644
--- a/Source/include/task.h
+++ b/Source/include/task.h
@@ -47,11 +47,12 @@
 	licensing and training services.
 */
 
-/*
-Changes since V4.3.1:
 
-	+ Added xTaskGetSchedulerState() function.
-*/
+#ifndef INC_FREERTOS_H
+	#error "#include FreeRTOS.h" must appear in source files before "#include task.h"
+#endif
+
+
 
 #ifndef TASK_H
 #define TASK_H