diff --git a/aq_programmer.c b/aq_programmer.c
index d9c78b48..97aee966 100644
--- a/aq_programmer.c
+++ b/aq_programmer.c
@@ -88,7 +88,7 @@ void _aq_programmer(program_type r_type, char *args, struct aqualinkdata *aq_dat
 
 #define MAX_STACK 20
 int _stack_place = 0;
-unsigned char _commands[MAX_STACK];
+static unsigned char _commands[MAX_STACK];
 //unsigned char pgm_commands[MAX_STACK];
 unsigned char _pgm_command = NUL;
 //unsigned char _ot_pgm_command = NUL;
diff --git a/simulator.c b/simulator.c
index 709574e4..2e3e96e5 100644
--- a/simulator.c
+++ b/simulator.c
@@ -9,7 +9,7 @@
 
 #define MAX_STACK 20
 int _sim_stack_place = 0;
-unsigned char _commands[MAX_STACK];
+static unsigned char _commands[MAX_STACK];
 
 bool push_simulator_cmd(unsigned char cmd);
 
@@ -136,4 +136,4 @@ bool is_simulator_packet(struct aqualinkdata *aqdata, unsigned char *packet, int
     } else {
       return false;
     }
-}
\ No newline at end of file
+}