diff --git a/include/xo/arena/AllocInfo.hpp b/include/xo/arena/AllocInfo.hpp
index 599e0b7..16878b9 100644
--- a/include/xo/arena/AllocInfo.hpp
+++ b/include/xo/arena/AllocInfo.hpp
@@ -78,7 +78,7 @@ namespace xo {
             /** Number of guard bytes **/
             size_type  guard_z() const noexcept { return p_config_->guard_z_; }
             /** Value (fixed test pattern) of guard byte **/
-            char guard_byte() const noexcept { return p_config_->guard_byte_; }
+            uint8_t guard_byte() const noexcept { return p_config_->guard_byte_; }
 
             ///@}
 
diff --git a/include/xo/arena/DArena.hpp b/include/xo/arena/DArena.hpp
index 13850d7..f485b3d 100644
--- a/include/xo/arena/DArena.hpp
+++ b/include/xo/arena/DArena.hpp
@@ -128,7 +128,7 @@ namespace xo {
              **/
             bool contains(const void * addr) const noexcept { return (lo_ <= addr) && (addr < hi_); }
 
-            /** Truee iff address @p addr is owned by this arena and in allocated regions **/
+            /** True iff address @p addr is owned by this arena and in allocated regions **/
             bool contains_allocated(const void * addr) const noexcept { return (lo_ <= addr) && (addr < free_); }
 
             /** true if arena is mapped i.e. has a reserved address range **/