diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -13804,6 +13804,13 @@
   if (InRange && IsEnumConstOrFromMacro(S, Constant))
     return false;
 
+  // Don't warn if the comparison involves the 'size_t' type.
+  QualType SizeT = S.Context.getSizeType();
+  if (S.Context.hasSameType(Constant->getType().getCanonicalType(), SizeT) &&
+      S.Context.hasSameType(Other->getType().getCanonicalType(), SizeT)) {
+    return false;
+  }
+
   // A comparison of an unsigned bit-field against 0 is really a type problem,
   // even though at the type level the bit-field might promote to 'signed int'.
   if (Other->refersToBitField() && InRange && Value == 0 &&
diff --git a/clang/test/Sema/type-limit-compare.cpp b/clang/test/Sema/type-limit-compare.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/Sema/type-limit-compare.cpp
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 %s -fsyntax-only -Wtautological-type-limit-compare -verify
+
+// expected-no-diagnostics
+
+typedef unsigned long uint64_t;
+namespace std {
+using size_t = decltype(sizeof(0));
+} // namespace std
+
+bool func(uint64_t Size) {
+  if (sizeof(std::size_t) < sizeof(uint64_t) &&
+     Size > (uint64_t)(__SIZE_MAX__))
+    return false;
+  return true;
+}
+