diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 4d02dfe57..3165b036e 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -3848,10 +3848,10 @@ bool Tokenizer::simplifyCalculations()
         }
 
         // (1-2)
-        if (Token::Match(tok, "[[,(=<>+-*] %num% [+-*/] %num% [],);=<>+-*/]") ||
-            Token::Match(tok, "<< %num% [+-*/] %num% [],);=<>+-*/]") ||
-            Token::Match(tok, "[[,(=<>+-*] %num% [+-*/] %num% <<") ||
-            Token::Match(tok, "<< %num% [+-*/] %num% <<"))
+        while (Token::Match(tok, "[[,(=<>+-*] %num% [+-*/] %num% [],);=<>+-*/]") ||
+               Token::Match(tok, "<< %num% [+-*/] %num% [],);=<>+-*/]") ||
+               Token::Match(tok, "[[,(=<>+-*] %num% [+-*/] %num% <<") ||
+               Token::Match(tok, "<< %num% [+-*/] %num% <<"))
         {
             tok = tok->next();
 
@@ -3877,7 +3877,7 @@ bool Tokenizer::simplifyCalculations()
             // instead of ((2 + 2) - (2 - 2)) = 4
             if (Token::Match(tok->next(), "[+-*/]"))
             {
-                tok = tok->tokAt(-2);
+                tok = tok->previous();
                 continue;
             }
 
diff --git a/test/testpreprocessor.cpp b/test/testpreprocessor.cpp
index 0f885a9b7..3c7299cac 100644
--- a/test/testpreprocessor.cpp
+++ b/test/testpreprocessor.cpp
@@ -100,6 +100,7 @@ private:
         TEST_CASE(if_cond5);
         TEST_CASE(if_cond6);
         TEST_CASE(if_cond7);
+        TEST_CASE(if_cond8);
 
         TEST_CASE(if_or);
 
@@ -836,6 +837,25 @@ private:
     }
 
 
+    void if_cond8()
+    {
+        const char filedata[] = "#if defined(A) + defined(B) + defined(C) != 1\n"
+                                "#endif\n";
+
+        // Preprocess => actual result..
+        std::istringstream istr(filedata);
+        std::map<std::string, std::string> actual;
+        Settings settings;
+        Preprocessor preprocessor(&settings, this);
+        preprocessor.preprocess(istr, actual, "file.c");
+
+        // Compare results..
+        ASSERT_EQUALS(1, actual.size());
+        ASSERT_EQUALS("\n\n", actual[""]);
+    }
+
+
+
     void if_or()
     {
         const char filedata[] = "#if defined(DEF_10) || defined(DEF_11)\n"