diff --git a/cli/cmdlineparser.cpp b/cli/cmdlineparser.cpp
index 924009ed018..6e01cd10116 100644
--- a/cli/cmdlineparser.cpp
+++ b/cli/cmdlineparser.cpp
@@ -1264,7 +1264,7 @@ CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const a
                 else if (std::strncmp(std.c_str(), "c", 1) == 0) {
                     mSettings.standards.c = Standards::getC(std);
                 }
-                else {
+                if (!validateStandard(std)) {
                     mLogger.printError("unknown --std value '" + std + "'");
                     return Result::Fail;
                 }
@@ -1943,3 +1943,18 @@ bool CmdLineParser::loadCppcheckCfg()
     return true;
 }
 
+bool CmdLineParser::validateStandard(const std::string &std)
+{
+        return std == "c++03"
+            || std == "c++11"
+            || std == "c++14"
+            || std == "c++17"
+            || std == "c++20"
+            || std == "c++23"
+            || std == "c++26"
+            || std == "c89"
+            || std == "c99"
+            || std == "c11"
+            || std == "c17"
+            || std == "c23";
+}
diff --git a/cli/cmdlineparser.h b/cli/cmdlineparser.h
index b1abdd1222b..f8023bfd6f9 100644
--- a/cli/cmdlineparser.h
+++ b/cli/cmdlineparser.h
@@ -156,6 +156,8 @@ class CmdLineParser {
 
     bool loadCppcheckCfg();
 
+    static bool validateStandard(const std::string &std);
+
     CmdLineLogger &mLogger;
 
     std::vector<std::string> mPathNames;
diff --git a/test/testcmdlineparser.cpp b/test/testcmdlineparser.cpp
index 46425aa161f..b7c46dd5a6f 100644
--- a/test/testcmdlineparser.cpp
+++ b/test/testcmdlineparser.cpp
@@ -1369,8 +1369,8 @@ class TestCmdlineParser : public TestFixture {
     void stdunknown2() {
         REDIRECT;
         const char *const argv[] = {"cppcheck", "--std=cplusplus11", "file.cpp"};
-        TODO_ASSERT_EQUALS(static_cast<int>(CmdLineParser::Result::Fail), static_cast<int>(CmdLineParser::Result::Success), static_cast<int>(parser->parseFromArgs(3, argv)));
-        TODO_ASSERT_EQUALS("cppcheck: error: unknown --std value 'cplusplus11'\n", "", logger->str());
+        ASSERT_EQUALS(static_cast<int>(CmdLineParser::Result::Fail), static_cast<int>(parser->parseFromArgs(3, argv)));
+        ASSERT_EQUALS("cppcheck: error: unknown --std value 'cplusplus11'\n", logger->str());
     }
 
     void platformWin64() {