Index: clang-tidy/readability/UppercaseLiteralSuffixCheck.cpp
===================================================================
--- clang-tidy/readability/UppercaseLiteralSuffixCheck.cpp
+++ clang-tidy/readability/UppercaseLiteralSuffixCheck.cpp
@@ -198,7 +198,8 @@
   Finder->addMatcher(
       stmt(allOf(eachOf(integerLiteral().bind(IntegerLiteralCheck::Name),
                         floatLiteral().bind(FloatingLiteralCheck::Name)),
-                 unless(hasParent(userDefinedLiteral())))),
+                 unless(anyOf(hasParent(userDefinedLiteral()),
+                              hasParent(substNonTypeTemplateParmExpr()))))),
       this);
 }
 
Index: test/clang-tidy/readability-uppercase-literal-suffix-integer.cpp
===================================================================
--- test/clang-tidy/readability-uppercase-literal-suffix-integer.cpp
+++ test/clang-tidy/readability-uppercase-literal-suffix-integer.cpp
@@ -243,3 +243,11 @@
 void user_defined_literals() {
   1_ull;
 }
+
+template <unsigned alignment>
+void template_test() {
+  static_assert(alignment, "");
+}
+void actual_template_test() {
+  template_test<4>();
+}