diff --git a/clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
index 5bdf01c098dc6d..4c537afd3347bd 100644
--- a/clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SizeofExpressionCheck.cpp
@@ -20,7 +20,7 @@ namespace bugprone {
 namespace {
 
 AST_MATCHER_P(IntegerLiteral, isBiggerThan, unsigned, N) {
-  return Node.getValue().getZExtValue() > N;
+  return Node.getValue().ugt(N);
 }
 
 AST_MATCHER_P2(Expr, hasSizeOfDescendant, int, Depth,
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 2d144aae75e654..729bb3bbd7365c 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -122,6 +122,9 @@ Changes in existing checks
 - Fixed a false positive in :doc:`misc-redundant-expression <clang-tidy/checks/misc-redundant-expression>`
   involving overloaded comparison operators.
 
+- Fixed a crash in :doc:`bugprone-sizeof-expression <clang-tidy/checks/bugprone-sizeof-expression>` when
+  `sizeof(...)` is compared agains a `__int128_t`.
+
 Removed checks
 ^^^^^^^^^^^^^^
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone-sizeof-expression.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone-sizeof-expression.cpp
index 21d4532294aafa..605243cf7a7820 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone-sizeof-expression.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone-sizeof-expression.cpp
@@ -172,7 +172,10 @@ int Foo() { int A[T]; return sizeof(T); }
 template <typename T>
 int Bar() { T A[5]; return sizeof(A[0]) / sizeof(T); }
 // CHECK-MESSAGES: :[[@LINE-1]]:28: warning: suspicious usage of sizeof pointer 'sizeof(T)/sizeof(T)'
-int Test3() { return Foo<42>() + Bar<char>(); }
+template <__int128_t N> 
+bool Baz() { return sizeof(A) < N; }
+// CHECK-MESSAGES: :[[@LINE-1]]:21: warning: suspicious comparison of 'sizeof(expr)' to a constant
+int Test3() { return Foo<42>() + Bar<char>() + Baz<-1>(); }
 
 static const char* kABC = "abc";
 static const wchar_t* kDEF = L"def";