diff --git a/io-helper.h b/io-helper.h
index 795e8df..779f8ae 100644
--- a/io-helper.h
+++ b/io-helper.h
@@ -1,5 +1,12 @@
+#ifndef _IO_HELPER_
+#define _IO_HELPER_
+
+#include <stdint.h>
+
 extern volatile uint8_t outStates[4]; 
 extern volatile uint8_t inStates[4];
+extern volatile uint8_t ioHelperDebounceTable[32];
+
 void ioHelperSetOuts(void);
 void ioHelperReadPins(void);
 void ioHelperIoConf(void);
@@ -17,3 +24,5 @@ void ioHelperDebounce(void);
 //Pin | Bit in inStates
 #define BitPinC1 0
 #define BitPinC5 1
+
+#endif