diff --git a/client/cmddata.c b/client/cmddata.c
index d27ca18bb..5d012199f 100644
--- a/client/cmddata.c
+++ b/client/cmddata.c
@@ -561,7 +561,7 @@ int CmdManchesterDemod(const char *Cmd)
 
   /* But it does not work if compiling on WIndows: therefore we just allocate a */
   /* large array */
-  int BitStream[MAX_GRAPH_TRACE_LEN];
+  uint8_t BitStream[MAX_GRAPH_TRACE_LEN];
 
   /* Detect high and lows */
   for (i = 0; i < GraphTraceLen; i++)
diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c
index 37355ef26..09bd1920f 100644
--- a/client/cmdlfem4x.c
+++ b/client/cmdlfem4x.c
@@ -34,7 +34,7 @@ int CmdEM410xRead(const char *Cmd)
   int parity[4];
   char id[11];
   int retested = 0;
-  int BitStream[MAX_GRAPH_TRACE_LEN];
+  uint8_t BitStream[MAX_GRAPH_TRACE_LEN];
   high = low = 0;
 
   /* Detect high and lows and clock */