diff --git a/src/libcoreint/interpreter.c b/src/libcoreint/interpreter.c
index f497629f8..7ba03e17d 100644
--- a/src/libcoreint/interpreter.c
+++ b/src/libcoreint/interpreter.c
@@ -32,12 +32,12 @@ gen_bytecode ()
     wait(500);
    }
    */
-//  save_op_data (0, getop_loop_inf (1));
-//  save_op_data (1, getop_call_1 (0, 12));
-//  save_op_data (2, getop_call_1 (0, 13));
-//  save_op_data (3, getop_call_1 (0, 14));
-//  save_op_data (4, getop_call_1 (0, 15));
-//  save_op_data (5, getop_jmp (0));
+  //  save_op_data (0, getop_loop_inf (1));
+  //  save_op_data (1, getop_call_1 (0, 12));
+  //  save_op_data (2, getop_call_1 (0, 13));
+  //  save_op_data (3, getop_call_1 (0, 14));
+  //  save_op_data (4, getop_call_1 (0, 15));
+  //  save_op_data (5, getop_jmp (0));
 
 #ifdef __MCU
   // It's mandatory to restart app!
@@ -49,8 +49,7 @@ void
 init_int ()
 {
 #define INIT_OP_FUNC(name) __opfuncs[ name ] = opfunc_##name ;
-  // FIXME
-  // JERRY_STATIC_ASSERT (sizeof (OPCODE) <= 4);
+  JERRY_STATIC_ASSERT (sizeof (OPCODE) <= 4);
 
   OP_LIST (INIT_OP_FUNC)
 }
@@ -65,7 +64,7 @@ run_int ()
 
   while (true)
   {
-    run_int_from_pos(&int_data);
+    run_int_from_pos (&int_data);
   }
 }
 
diff --git a/src/libcoreint/interpreter.h b/src/libcoreint/interpreter.h
index 9e1a993eb..df556e39c 100644
--- a/src/libcoreint/interpreter.h
+++ b/src/libcoreint/interpreter.h
@@ -31,10 +31,10 @@ opfunc __opfuncs[LAST_OP];
 
 struct __int_data
 {
-  int pos;
+  int pos; /**< current opcode to execute */
   ecma_Object_t *pThisBinding; /**< this binding for current context */
   ecma_Object_t *pLexEnv; /**< current lexical environment */
-  int *root_op_addr;
+  int *root_op_addr; /**< pointer to first opcode saved */
 };
 
 void gen_bytecode (void);