diff --git a/cli/cmdlineparser.cpp b/cli/cmdlineparser.cpp
index 6e5589042..f5277e6ef 100644
--- a/cli/cmdlineparser.cpp
+++ b/cli/cmdlineparser.cpp
@@ -377,10 +377,6 @@ bool CmdLineParser::ParseFromArgs(int argc, const char* const argv[])
             if (define.find("=") == std::string::npos)
                 define += "=1";
 
-            // DEF= => empty define
-            else if (define.find("=") + 1U == define.size())
-                define.erase(define.size() - 1U);
-
             if (!_settings->userDefines.empty())
                 _settings->userDefines += ";";
             _settings->userDefines += define;
diff --git a/test/testcmdlineparser.cpp b/test/testcmdlineparser.cpp
index 1cf4e4765..d3ad863d4 100644
--- a/test/testcmdlineparser.cpp
+++ b/test/testcmdlineparser.cpp
@@ -346,10 +346,10 @@ private:
 
     void defines4() {
         REDIRECT;
-        const char *argv[] = {"cppcheck", "-DDEBUG=", "file.cpp"};
+        const char *argv[] = {"cppcheck", "-DDEBUG=", "file.cpp"}; // #5137 - defining empty macro
         settings.userDefines.clear();
         ASSERT(defParser.ParseFromArgs(3, argv));
-        ASSERT_EQUALS("DEBUG", settings.userDefines);
+        ASSERT_EQUALS("DEBUG=", settings.userDefines);
     }
 
     void enforceLanguage() {