diff --git a/include/bitcoin/system/arena.hpp b/include/bitcoin/system/arena.hpp
index 68ce919331..8a0d7998fb 100644
--- a/include/bitcoin/system/arena.hpp
+++ b/include/bitcoin/system/arena.hpp
@@ -54,16 +54,16 @@ class arena
     /// Non-linear allocator just returns next address.
     /// Linear allocator resets to and returns buffer first address.
     /// Detachable linear allocator allocates buffer returns its first address.
-    virtual void* start() NOEXCEPT = 0;
+    virtual void* start(size_t baseline) THROWS = 0;
 
     /// Non-linear allocator just returns zero.
     /// Linear allocator returns current allocation size.
     /// Detachable linear allocator detaches allocation and returns its size.
-    virtual size_t detach() NOEXCEPT = 0;
+    virtual size_t detach() THROWS = 0;
 
     /// Non-linear and linear allocator is a nop.
-    /// Detachable linear allocator frees the memory associated with ptr.
-    virtual void release(void* ptr, size_t bytes) NOEXCEPT = 0;
+    /// Detachable linear allocator frees the memory associated with memory.
+    virtual void release(void* memory) NOEXCEPT = 0;
 
 private:
     virtual void* do_allocate(size_t bytes, size_t align) THROWS = 0;
@@ -93,9 +93,9 @@ class BC_API default_arena final
 {
 public:
     static arena* get() NOEXCEPT;
-    void* start() NOEXCEPT override;
-    size_t detach() NOEXCEPT override;
-    void release(void* ptr, size_t bytes) NOEXCEPT override;
+    void* start(size_t baseline) THROWS override;
+    size_t detach() THROWS override;
+    void release(void* address) NOEXCEPT override;
 
 private:
     void* do_allocate(size_t bytes, size_t align) THROWS override;
diff --git a/src/arena.cpp b/src/arena.cpp
index 3ae19bbbea..a8b3cc7ca4 100644
--- a/src/arena.cpp
+++ b/src/arena.cpp
@@ -57,17 +57,17 @@ bool default_arena::do_is_equal(const arena& other) const NOEXCEPT
     return &other == this;
 }
 
-void* default_arena::start() NOEXCEPT
+void* default_arena::start(size_t) THROWS
 {
     return nullptr;
 }
 
-size_t default_arena::detach() NOEXCEPT
+size_t default_arena::detach() THROWS
 {
     return zero;
 }
 
-void default_arena::release(void*, size_t) NOEXCEPT
+void default_arena::release(void*) NOEXCEPT
 {
 }
 
diff --git a/test/test.hpp b/test/test.hpp
index 149c94ce18..bd5df89dc3 100644
--- a/test/test.hpp
+++ b/test/test.hpp
@@ -127,17 +127,17 @@ class reporting_arena
     size_t dec_count{};
     size_t dec_bytes{};
 
-    void* start() NOEXCEPT override
+    void* start(size_t) THROWS override
     {
         return nullptr;
     }
 
-    size_t detach() NOEXCEPT override
+    size_t detach() THROWS override
     {
         return zero;
     }
 
-    void release(void*, size_t) NOEXCEPT override
+    void release(void*) NOEXCEPT override
     {
     }
 
@@ -198,17 +198,17 @@ class mock_arena
     size_t do_deallocate_align{};
     mutable const arena* do_is_equal_address{};
 
-    void* start() NOEXCEPT override
+    void* start(size_t) THROWS override
     {
         return nullptr;
     }
 
-    size_t detach() NOEXCEPT override
+    size_t detach() THROWS override
     {
         return zero;
     }
 
-    void release(void*, size_t) NOEXCEPT override
+    void release(void*) NOEXCEPT override
     {
     }