diff --git a/lib/preprocessor.cpp b/lib/preprocessor.cpp
index 3b175eabf..45f0b3c70 100644
--- a/lib/preprocessor.cpp
+++ b/lib/preprocessor.cpp
@@ -705,7 +705,7 @@ std::list<std::string> Preprocessor::getcfgs(const std::string &filedata, const
                     varmap[varname] = value;
                 }
 
-                simplifyCondition(varmap, def);
+                simplifyCondition(varmap, def, false);
             }
 
             if (! deflist.empty() && line.find("#elif ") == 0)
@@ -917,7 +917,7 @@ std::list<std::string> Preprocessor::getcfgs(const std::string &filedata, const
 }
 
 
-void Preprocessor::simplifyCondition(const std::map<std::string, std::string> &variables, std::string &condition)
+void Preprocessor::simplifyCondition(const std::map<std::string, std::string> &variables, std::string &condition, bool match)
 {
     Tokenizer tokenizer;
     std::istringstream istr(("(" + condition + ")").c_str());
@@ -931,10 +931,12 @@ void Preprocessor::simplifyCondition(const std::map<std::string, std::string> &v
 
         if (Token::Match(tok, "defined ( %var% )"))
         {
-            if (variables.find(tok->strAt(2)) == variables.end())
+            if (variables.find(tok->strAt(2)) != variables.end())
+                tok->str("1");
+            else if (match)
                 tok->str("0");
             else
-                tok->str("1");
+                continue;
             tok->deleteNext();
             tok->deleteNext();
             tok->deleteNext();
@@ -943,10 +945,12 @@ void Preprocessor::simplifyCondition(const std::map<std::string, std::string> &v
 
         if (Token::Match(tok, "defined %var%"))
         {
-            if (variables.find(tok->strAt(1)) == variables.end())
+            if (variables.find(tok->strAt(1)) != variables.end())
+                tok->str("1");
+            else if (match)
                 tok->str("0");
             else
-                tok->str("1");
+                continue;
             tok->deleteNext();
             continue;
         }
@@ -990,7 +994,7 @@ bool Preprocessor::match_cfg_def(const std::map<std::string, std::string> &cfg,
     //std::cout << "cfg: \"" << cfg << "\"  ";
     //std::cout << "def: \"" << def << "\"";
 
-    simplifyCondition(cfg, def);
+    simplifyCondition(cfg, def, true);
 
     if (cfg.find(def) != cfg.end())
         return true;
diff --git a/lib/preprocessor.h b/lib/preprocessor.h
index 12a46b514..be98fa6ca 100644
--- a/lib/preprocessor.h
+++ b/lib/preprocessor.h
@@ -87,8 +87,9 @@ public:
      * simplify condition
      * @param variables Variable values
      * @param condition The condition to simplify
+     * @param match if true, 'defined(A)' is replaced with 0 if A is not defined
      */
-    static void simplifyCondition(const std::map<std::string, std::string> &variables, std::string &condition);
+    static void simplifyCondition(const std::map<std::string, std::string> &variables, std::string &condition, bool match);
 
 protected:
 
diff --git a/test/testcppcheck.cpp b/test/testcppcheck.cpp
index 6971b48df..bf1f1fe51 100644
--- a/test/testcppcheck.cpp
+++ b/test/testcppcheck.cpp
@@ -67,7 +67,8 @@ private:
         check(filedata);
 
         // Compare results..
-        ASSERT_EQUALS("[file.cpp:5]: (error) Dereferencing 'foo' after it is deallocated / released\n", errout.str());
+        ASSERT_EQUALS("Checking file.cpp...\n"
+                      "[file.cpp:5]: (error) Dereferencing 'foo' after it is deallocated / released\n", errout.str());
     }
 
     void linenumbers2()
diff --git a/test/testpreprocessor.cpp b/test/testpreprocessor.cpp
index ff3c59f50..0f61736c7 100644
--- a/test/testpreprocessor.cpp
+++ b/test/testpreprocessor.cpp
@@ -101,6 +101,8 @@ private:
         TEST_CASE(if_cond6);
         TEST_CASE(if_cond7);
 
+        TEST_CASE(if_or);
+
         TEST_CASE(multiline1);
         TEST_CASE(multiline2);
         TEST_CASE(multiline3);
@@ -834,6 +836,35 @@ private:
     }
 
 
+    void if_or()
+    {
+        const char filedata[] = "#if defined(DEF_10) || defined(DEF_11)\n"
+                                "a1;\n"
+                                "#endif\n";
+
+        errout.str("");
+
+        // Preprocess => actual result..
+        std::istringstream istr(filedata);
+        std::map<std::string, std::string> actual;
+        Settings settings;
+        settings._verbose = true;
+        settings._debug = true;
+        Preprocessor preprocessor(&settings, this);
+        preprocessor.preprocess(istr, actual, "file.c");
+
+        // Compare results..
+        ASSERT_EQUALS(1, actual.size());
+        ASSERT_EQUALS("\n\n\n", actual[""]);
+
+        // the "defined(DEF_10) || defined(DEF_11)" are not handled correctly..
+        ASSERT_EQUALS("unhandled configuration: defined(DEF_10)||defined(DEF_11)\n", errout.str());
+        TODO_ASSERT_EQUALS(2, actual.size());
+        TODO_ASSERT_EQUALS("\na1;\n\n", actual["DEF_10"]);
+
+    }
+
+
     void multiline1()
     {
         const char filedata[] = "#define str \"abc\"     \\\n"
diff --git a/test/testsuite.cpp b/test/testsuite.cpp
index 215eb210e..abb175618 100644
--- a/test/testsuite.cpp
+++ b/test/testsuite.cpp
@@ -180,9 +180,9 @@ size_t TestFixture::runTests(const char cmd[])
     return fails_counter;
 }
 
-void TestFixture::reportOut(const std::string & /*outmsg*/)
+void TestFixture::reportOut(const std::string & outmsg)
 {
-    // These can probably be ignored
+    errout << outmsg << std::endl;
 }
 
 void TestFixture::reportErr(const ErrorLogger::ErrorMessage &msg)