diff --git a/extras/tests/Helpers/Allocators.hpp b/extras/tests/Helpers/Allocators.hpp
index 06984b82..027d5aa7 100644
--- a/extras/tests/Helpers/Allocators.hpp
+++ b/extras/tests/Helpers/Allocators.hpp
@@ -29,29 +29,79 @@ struct FailingAllocator : ArduinoJson::Allocator {
   }
 };
 
-class SpyingAllocator : public ArduinoJson::Allocator {
+class AllocatorLog {
  public:
-  virtual ~SpyingAllocator() {}
+  struct Allocate {
+    Allocate(size_t s) : size(s) {}
+    size_t size;
+  };
 
-  void* allocate(size_t n) override {
-    _log << "A" << n;
-    return malloc(n);
+  struct Reallocate {
+    Reallocate(size_t s) : size(s) {}
+    size_t size;
+  };
+
+  struct Deallocate {};
+
+  AllocatorLog& operator<<(const Allocate& a) {
+    _log << "allocate(" << a.size << ")\n";
+    return *this;
   }
 
-  void deallocate(void* p) override {
-    _log << "F";
-    free(p);
+  AllocatorLog& operator<<(const Deallocate&) {
+    _log << "deallocate()\n";
+    return *this;
   }
 
-  void* reallocate(void* ptr, size_t n) override {
-    _log << "R" << n;
-    return realloc(ptr, n);
+  AllocatorLog& operator<<(const Reallocate& a) {
+    _log << "reallocate(" << a.size << ")\n";
+    return *this;
   }
 
-  std::string log() const {
-    return _log.str();
+  std::string str() const {
+    auto s = _log.str();
+    if (s.empty())
+      return "(empty)";
+    s.pop_back();  // remove the trailing '\n'
+    return s;
+  }
+
+  bool operator==(const AllocatorLog& other) const {
+    return str() == other.str();
+  }
+
+  friend std::ostream& operator<<(std::ostream& os, const AllocatorLog& log) {
+    os << log.str();
+    return os;
   }
 
  private:
   std::ostringstream _log;
 };
+
+class SpyingAllocator : public ArduinoJson::Allocator {
+ public:
+  virtual ~SpyingAllocator() {}
+
+  void* allocate(size_t n) override {
+    _log << AllocatorLog::Allocate(n);
+    return malloc(n);
+  }
+
+  void deallocate(void* p) override {
+    _log << AllocatorLog::Deallocate();
+    free(p);
+  }
+
+  void* reallocate(void* ptr, size_t n) override {
+    _log << AllocatorLog::Reallocate(n);
+    return realloc(ptr, n);
+  }
+
+  const AllocatorLog& log() const {
+    return _log;
+  }
+
+ private:
+  AllocatorLog _log;
+};
diff --git a/extras/tests/JsonDocument/allocator.cpp b/extras/tests/JsonDocument/allocator.cpp
index 920d1475..472b0830 100644
--- a/extras/tests/JsonDocument/allocator.cpp
+++ b/extras/tests/JsonDocument/allocator.cpp
@@ -42,7 +42,9 @@ TEST_CASE("JsonDocument's allocator") {
 
   SECTION("Construct/Destruct") {
     { JsonDocument doc(4096, &spyingAllocator); }
-    REQUIRE(spyingAllocator.log() == "A4096F");
+    REQUIRE(spyingAllocator.log() == AllocatorLog()
+                                         << AllocatorLog::Allocate(4096)
+                                         << AllocatorLog::Deallocate());
   }
 
   SECTION("Copy construct") {
@@ -56,7 +58,11 @@ TEST_CASE("JsonDocument's allocator") {
       REQUIRE(doc2.as<std::string>() == "The size of this string is 32!!");
       REQUIRE(doc2.capacity() == 4096);
     }
-    REQUIRE(spyingAllocator.log() == "A4096A4096FF");
+    REQUIRE(spyingAllocator.log() == AllocatorLog()
+                                         << AllocatorLog::Allocate(4096)
+                                         << AllocatorLog::Allocate(4096)
+                                         << AllocatorLog::Deallocate()
+                                         << AllocatorLog::Deallocate());
   }
 
   SECTION("Move construct") {
@@ -71,7 +77,9 @@ TEST_CASE("JsonDocument's allocator") {
       REQUIRE(doc1.capacity() == 0);
       REQUIRE(doc2.capacity() == 4096);
     }
-    REQUIRE(spyingAllocator.log() == "A4096F");
+    REQUIRE(spyingAllocator.log() == AllocatorLog()
+                                         << AllocatorLog::Allocate(4096)
+                                         << AllocatorLog::Deallocate());
   }
 
   SECTION("Copy assign larger") {
@@ -86,7 +94,13 @@ TEST_CASE("JsonDocument's allocator") {
       REQUIRE(doc2.as<std::string>() == "The size of this string is 32!!");
       REQUIRE(doc2.capacity() == 4096);
     }
-    REQUIRE(spyingAllocator.log() == "A4096A8FA4096FF");
+    REQUIRE(spyingAllocator.log() == AllocatorLog()
+                                         << AllocatorLog::Allocate(4096)
+                                         << AllocatorLog::Allocate(8)
+                                         << AllocatorLog::Deallocate()
+                                         << AllocatorLog::Allocate(4096)
+                                         << AllocatorLog::Deallocate()
+                                         << AllocatorLog::Deallocate());
   }
 
   SECTION("Copy assign smaller") {
@@ -101,7 +115,13 @@ TEST_CASE("JsonDocument's allocator") {
       REQUIRE(doc2.as<std::string>() == "The size of this string is 32!!");
       REQUIRE(doc2.capacity() == 1024);
     }
-    REQUIRE(spyingAllocator.log() == "A1024A4096FA1024FF");
+    REQUIRE(spyingAllocator.log() == AllocatorLog()
+                                         << AllocatorLog::Allocate(1024)
+                                         << AllocatorLog::Allocate(4096)
+                                         << AllocatorLog::Deallocate()
+                                         << AllocatorLog::Allocate(1024)
+                                         << AllocatorLog::Deallocate()
+                                         << AllocatorLog::Deallocate());
   }
 
   SECTION("Copy assign same size") {
@@ -116,7 +136,11 @@ TEST_CASE("JsonDocument's allocator") {
       REQUIRE(doc2.as<std::string>() == "The size of this string is 32!!");
       REQUIRE(doc2.capacity() == 1024);
     }
-    REQUIRE(spyingAllocator.log() == "A1024A1024FF");
+    REQUIRE(spyingAllocator.log() == AllocatorLog()
+                                         << AllocatorLog::Allocate(1024)
+                                         << AllocatorLog::Allocate(1024)
+                                         << AllocatorLog::Deallocate()
+                                         << AllocatorLog::Deallocate());
   }
 
   SECTION("Move assign") {
@@ -132,7 +156,11 @@ TEST_CASE("JsonDocument's allocator") {
       REQUIRE(doc1.capacity() == 0);
       REQUIRE(doc2.capacity() == 4096);
     }
-    REQUIRE(spyingAllocator.log() == "A4096A8FF");
+    REQUIRE(spyingAllocator.log() == AllocatorLog()
+                                         << AllocatorLog::Allocate(4096)
+                                         << AllocatorLog::Allocate(8)
+                                         << AllocatorLog::Deallocate()
+                                         << AllocatorLog::Deallocate());
   }
 
   SECTION("garbageCollect()") {