diff --git a/src/BLEStringCharacteristic.cpp b/src/BLEStringCharacteristic.cpp
index 76f0812c..a12e722d 100644
--- a/src/BLEStringCharacteristic.cpp
+++ b/src/BLEStringCharacteristic.cpp
@@ -19,7 +19,7 @@
 
 #include "BLEStringCharacteristic.h"
 
-BLEStringCharacteristic::BLEStringCharacteristic(const char* uuid, unsigned char properties, int valueSize) :
+BLEStringCharacteristic::BLEStringCharacteristic(const char* uuid, unsigned int properties, int valueSize) :
   BLECharacteristic(uuid, properties, valueSize)
 {
 }
diff --git a/src/BLEStringCharacteristic.h b/src/BLEStringCharacteristic.h
index c9f28fca..65604846 100644
--- a/src/BLEStringCharacteristic.h
+++ b/src/BLEStringCharacteristic.h
@@ -27,7 +27,7 @@
 class BLEStringCharacteristic : public BLECharacteristic
 {
 public:
-  BLEStringCharacteristic(const char* uuid, unsigned char properties, int valueSize);
+  BLEStringCharacteristic(const char* uuid, unsigned int properties, int valueSize);
 
   int writeValue(const String& value);
   int setValue(const String& value) { return writeValue(value); }