diff --git a/src/hotspot/share/services/memReporter.cpp b/src/hotspot/share/services/memReporter.cpp
index 7aa7311fdf4..92dbb801e02 100644
--- a/src/hotspot/share/services/memReporter.cpp
+++ b/src/hotspot/share/services/memReporter.cpp
@@ -31,6 +31,16 @@
 #include "services/virtualMemoryTracker.hpp"
 #include "utilities/globalDefinitions.hpp"
 
+// Diff two counters, express them as signed, with range checks
+static ssize_t counter_diff(size_t c1, size_t c2) {
+  assert(c1 <= SSIZE_MAX, "counter out of range: " SIZE_FORMAT ".", c1);
+  assert(c2 <= SSIZE_MAX, "counter out of range: " SIZE_FORMAT ".", c2);
+  if (c1 > SSIZE_MAX || c2 > SSIZE_MAX) {
+    return 0;
+  }
+  return c1 - c2;
+}
+
 size_t MemReporterBase::reserved_total(const MallocMemory* malloc, const VirtualMemory* vm) {
   return malloc->malloc_size() + malloc->arena_size() + vm->reserved();
 }
@@ -462,8 +472,9 @@ void MemSummaryDiffReporter::print_malloc_diff(size_t current_amount, size_t cur
   }
   if (current_count > 0) {
     out->print(" #" SIZE_FORMAT "", current_count);
-    if (current_count != early_count) {
-      out->print(" %+d", (int)(current_count - early_count));
+    const ssize_t delta_count = counter_diff(current_count, early_count);
+    if (delta_count != 0) {
+      out->print(" " SSIZE_PLUS_FORMAT, delta_count);
     }
   }
 }
@@ -478,8 +489,9 @@ void MemSummaryDiffReporter::print_arena_diff(size_t current_amount, size_t curr
   }
 
   out->print(" #" SIZE_FORMAT "", current_count);
-  if (current_count != early_count) {
-    out->print(" %+d", (int)(current_count - early_count));
+  const ssize_t delta_count = counter_diff(current_count, early_count);
+  if (delta_count != 0) {
+    out->print(" " SSIZE_PLUS_FORMAT, delta_count);
   }
 }
 
@@ -551,30 +563,33 @@ void MemSummaryDiffReporter::diff_summary_of_type(MEMFLAGS flag,
     if (flag == mtClass) {
       // report class count
       out->print("%27s (classes #" SIZE_FORMAT "", " ", _current_baseline.class_count());
-      int class_count_diff = (int)(_current_baseline.class_count() -
-        _early_baseline.class_count());
-      if (_current_baseline.class_count() != _early_baseline.class_count()) {
-        out->print(" %+d", (int)(_current_baseline.class_count() - _early_baseline.class_count()));
+      const ssize_t class_count_diff =
+          counter_diff(_current_baseline.class_count(), _early_baseline.class_count());
+      if (class_count_diff != 0) {
+        out->print(" " SSIZE_PLUS_FORMAT, class_count_diff);
       }
       out->print_cr(")");
 
       out->print("%27s (  instance classes #" SIZE_FORMAT, " ", _current_baseline.instance_class_count());
-      if (_current_baseline.instance_class_count() != _early_baseline.instance_class_count()) {
-        out->print(" %+d", (int)(_current_baseline.instance_class_count() - _early_baseline.instance_class_count()));
+      const ssize_t instance_class_count_diff =
+          counter_diff(_current_baseline.instance_class_count(), _early_baseline.instance_class_count());
+      if (instance_class_count_diff != 0) {
+        out->print(" " SSIZE_PLUS_FORMAT, instance_class_count_diff);
       }
       out->print(", array classes #" SIZE_FORMAT, _current_baseline.array_class_count());
-      if (_current_baseline.array_class_count() != _early_baseline.array_class_count()) {
-        out->print(" %+d", (int)(_current_baseline.array_class_count() - _early_baseline.array_class_count()));
+      const ssize_t array_class_count_diff =
+          counter_diff(_current_baseline.array_class_count(), _early_baseline.array_class_count());
+      if (array_class_count_diff != 0) {
+        out->print(" " SSIZE_PLUS_FORMAT, array_class_count_diff);
       }
       out->print_cr(")");
 
     } else if (flag == mtThread) {
       // report thread count
       out->print("%27s (thread #" SIZE_FORMAT "", " ", _current_baseline.thread_count());
-      int thread_count_diff = (int)(_current_baseline.thread_count() -
-          _early_baseline.thread_count());
+      const ssize_t thread_count_diff = counter_diff(_current_baseline.thread_count(), _early_baseline.thread_count());
       if (thread_count_diff != 0) {
-        out->print(" %+d", thread_count_diff);
+        out->print(" " SSIZE_PLUS_FORMAT, thread_count_diff);
       }
       out->print_cr(")");
 
diff --git a/src/hotspot/share/utilities/globalDefinitions.hpp b/src/hotspot/share/utilities/globalDefinitions.hpp
index 3771ac0f277..99eab62d2cf 100644
--- a/src/hotspot/share/utilities/globalDefinitions.hpp
+++ b/src/hotspot/share/utilities/globalDefinitions.hpp
@@ -130,6 +130,7 @@ class oopDesc;
 
 // Format integers which change size between 32- and 64-bit.
 #define SSIZE_FORMAT             "%"          PRIdPTR
+#define SSIZE_PLUS_FORMAT        "%+"         PRIdPTR
 #define SSIZE_FORMAT_W(width)    "%"   #width PRIdPTR
 #define SIZE_FORMAT              "%"          PRIuPTR
 #define SIZE_FORMAT_X            "0x%"        PRIxPTR
diff --git a/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp b/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp
index 2208953ee8b..9ea81ae7174 100644
--- a/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp
+++ b/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp
@@ -129,4 +129,14 @@ inline int g_isfinite(jdouble f)                 { return _finite(f); }
 #define USE_VECTORED_EXCEPTION_HANDLING
 #endif
 
+#ifndef SSIZE_MAX
+#ifdef _LP64
+#define SSIZE_MIN LLONG_MIN
+#define SSIZE_MAX LLONG_MAX
+#else
+#define SSIZE_MIN INT_MIN
+#define SSIZE_MAX INT_MAX
+#endif
+#endif // SSIZE_MAX missing
+
 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_VISCPP_HPP
diff --git a/test/hotspot/gtest/utilities/test_globalDefinitions.cpp b/test/hotspot/gtest/utilities/test_globalDefinitions.cpp
index ff18a1bd8f8..783bb6d326a 100644
--- a/test/hotspot/gtest/utilities/test_globalDefinitions.cpp
+++ b/test/hotspot/gtest/utilities/test_globalDefinitions.cpp
@@ -264,6 +264,13 @@ TEST(globalDefinitions, format_specifiers) {
   check_format(UINT64_FORMAT_W(-5),    (uint64_t)123,     "123  ");
 
   check_format(SSIZE_FORMAT,           (ssize_t)123,      "123");
+  check_format(SSIZE_FORMAT,           (ssize_t)-123,     "-123");
+  check_format(SSIZE_FORMAT,           (ssize_t)2147483647, "2147483647");
+  check_format(SSIZE_FORMAT,           (ssize_t)-2147483647, "-2147483647");
+  check_format(SSIZE_PLUS_FORMAT,      (ssize_t)123,      "+123");
+  check_format(SSIZE_PLUS_FORMAT,      (ssize_t)-123,     "-123");
+  check_format(SSIZE_PLUS_FORMAT,      (ssize_t)2147483647, "+2147483647");
+  check_format(SSIZE_PLUS_FORMAT,      (ssize_t)-2147483647, "-2147483647");
   check_format(SSIZE_FORMAT_W(5),      (ssize_t)123,      "  123");
   check_format(SSIZE_FORMAT_W(-5),     (ssize_t)123,      "123  ");
   check_format(SIZE_FORMAT,            (size_t)123u,      "123");