diff --git a/src/libs/3rdparty/cplusplus/Lexer.cpp b/src/libs/3rdparty/cplusplus/Lexer.cpp
index ac0b4a7ed60..db7cb9e0f83 100644
--- a/src/libs/3rdparty/cplusplus/Lexer.cpp
+++ b/src/libs/3rdparty/cplusplus/Lexer.cpp
@@ -853,6 +853,17 @@ bool Lexer::scanOptionalIntegerSuffix(bool allowU)
             scanOptionalIntegerSuffix(false);
         }
         return true;
+    case 'i':
+    case 'I':
+        yyinp();
+        if (_yychar == '6') {
+            yyinp();
+            if (_yychar == '4') {
+                yyinp();
+                return true;
+            }
+        }
+        return false;
     case 'l':
         yyinp();
         if (_yychar == 'l')
diff --git a/tests/auto/cplusplus/lexer/tst_lexer.cpp b/tests/auto/cplusplus/lexer/tst_lexer.cpp
index fc2b8da0476..ee4cd0499c4 100644
--- a/tests/auto/cplusplus/lexer/tst_lexer.cpp
+++ b/tests/auto/cplusplus/lexer/tst_lexer.cpp
@@ -336,6 +336,30 @@ void tst_SimpleLexer::literals_data()
                                ;
     QTest::newRow("integer-literals") << source << expectedTokenKindList;
 
+    source =
+            "42ui64\n"
+            "43UI64\n"
+            "44Ui64\n"
+            "45uI64\n"
+            "46i64\n"
+            "47I64\n"
+            "0xffffui64\n"
+            "0xfffeUi64\n"
+            "0xfffdi64\n"
+            "56ui\n"   // incomplete
+            "56ui6\n"
+            "57ui67\n" // wrong
+            "58i67\n"
+            ;
+    expectedTokenKindList =
+            TokenKindList() << T_NUMERIC_LITERAL << T_NUMERIC_LITERAL << T_NUMERIC_LITERAL
+                            << T_NUMERIC_LITERAL << T_NUMERIC_LITERAL << T_NUMERIC_LITERAL
+                            << T_NUMERIC_LITERAL << T_NUMERIC_LITERAL << T_NUMERIC_LITERAL
+                            << T_NUMERIC_LITERAL << T_NUMERIC_LITERAL
+                            << T_ERROR << T_ERROR
+                               ;
+    QTest::newRow("microsoft-suffix") << source << expectedTokenKindList;
+
     source =
             "R\"(raw text)\"\n"
             "R\"delimiter(raw text)delimiter\"\n"