diff --git a/include/microkernel.h b/include/microkernel.h
index d4e1721b5da..137d6a8e217 100644
--- a/include/microkernel.h
+++ b/include/microkernel.h
@@ -82,7 +82,6 @@ extern int K_StackSize;
 extern int K_PrioCount;
 extern int K_TaskCount;
 extern int K_MapCount;
-extern int K_MbxCount;
 extern int K_PoolCount;
 extern int K_PipeCount;
 extern const int K_max_eventnr;
diff --git a/kernel/microkernel/include/minik.h b/kernel/microkernel/include/minik.h
index 386daa2cf58..8700f47a76c 100644
--- a/kernel/microkernel/include/minik.h
+++ b/kernel/microkernel/include/minik.h
@@ -58,7 +58,6 @@ extern struct pipe_struct K_PipeList[];
 #ifndef LITE
 extern int K_MapCount;
 #endif
-extern int K_MbxCount;
 extern int K_PoolCount;
 extern int K_PipeCount;