diff --git a/libnfc/nfc-internal.h b/libnfc/nfc-internal.h
index 1bf8ab8..70d00db 100644
--- a/libnfc/nfc-internal.h
+++ b/libnfc/nfc-internal.h
@@ -41,7 +41,7 @@
     size_t __szPos; \
     printf(" %s: ", pcTag); \
     for (__szPos=0; __szPos < (size_t)(szBytes); __szPos++) { \
-      printf("%02x  ",pbtData[__szPos]); \
+      printf("%02x  ",((uint8_t *)(pbtData))[__szPos]); \
     } \
     printf("\n"); \
   } while (0);