diff --git a/lib/cppcheck.cpp b/lib/cppcheck.cpp
index c3a7a1999..57f3c30df 100644
--- a/lib/cppcheck.cpp
+++ b/lib/cppcheck.cpp
@@ -54,6 +54,19 @@ static TimerResults S_timerResults;
 // CWE ids used
 static const CWE CWE398(398U);  // Indicator of Poor Code Quality
 
+static std::vector<std::string> split(const std::string &str, const std::string &sep)
+{
+    std::vector<std::string> ret;
+    for (std::string::size_type defineStartPos = 0U; defineStartPos < str.size();) {
+        const std::string::size_type defineEndPos = str.find(sep, defineStartPos);
+        ret.push_back((defineEndPos == std::string::npos) ? str.substr(defineStartPos) : str.substr(defineStartPos, defineEndPos - defineStartPos));
+        if (defineEndPos == std::string::npos)
+            break;
+        defineStartPos = defineEndPos + 1U;
+    }
+    return ret;
+}
+
 CppCheck::CppCheck(ErrorLogger &errorLogger, bool useGlobalSuppressions)
     : mErrorLogger(errorLogger), mExitCode(0), mSuppressInternalErrorFound(false), mUseGlobalSuppressions(useGlobalSuppressions), mTooManyConfigs(false), mSimplify(true)
 {
@@ -325,12 +338,16 @@ unsigned int CppCheck::checkFile(const std::string& filename, const std::string
             if (!mSettings.force && ++checkCount > mSettings.maxConfigs)
                 break;
 
-            mCurrentConfig = currCfg;
-
             if (!mSettings.userDefines.empty()) {
-                if (!mCurrentConfig.empty())
-                    mCurrentConfig = ";" + mCurrentConfig;
-                mCurrentConfig = mSettings.userDefines + mCurrentConfig;
+                mCurrentConfig = mSettings.userDefines;
+                const std::vector<std::string> v1(split(mSettings.userDefines, ";"));
+                for (const std::string &cfg: split(currCfg, ";")) {
+                    if (std::find(v1.begin(), v1.end(), cfg) == v1.end()) {
+                        mCurrentConfig += ";" + cfg;
+                    }
+                }
+            } else {
+                mCurrentConfig = currCfg;
             }
 
             if (mSettings.preprocessOnly) {