diff --git a/lib/checkstring.cpp b/lib/checkstring.cpp
index 70e31ccdf..2236cea06 100644
--- a/lib/checkstring.cpp
+++ b/lib/checkstring.cpp
@@ -166,7 +166,7 @@ void CheckString::checkSuspiciousStringCompare()
             const Token* litTok = tok->astOperand2();
             if (!varTok || !litTok)  // <- failed to create AST for comparison
                 continue;
-            if (varTok->tokType() == Token::eString || varTok->tokType() == Token::eNumber)
+            if (Token::Match(varTok, "%char%|%num%|%str%"))
                 std::swap(varTok, litTok);
             else if (!Token::Match(litTok, "%char%|%num%|%str%"))
                 continue;
@@ -200,9 +200,7 @@ void CheckString::checkSuspiciousStringCompare()
                 varTok = varTok->astParent();
             const std::string varname = varTok->expressionString();
 
-            const bool ischar(litTok->tokType() == Token::eChar ||
-                              (!litTok->originalName().empty() &&
-                               litTok->originalName().front() == '\''));
+            const bool ischar(litTok->tokType() == Token::eChar);
             if (litTok->tokType() == Token::eString) {
                 if (_tokenizer->isC() || (var && var->isArrayOrPointer()))
                     suspiciousStringCompareError(tok, varname);
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 7ea58c03b..c42a97e33 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -1894,7 +1894,7 @@ void Tokenizer::simplifyNull()
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         if (tok->str() == "NULL" && (!Token::Match(tok->previous(), "[(,] NULL [,)]") || tok->strAt(-2) == "="))
             tok->str("0");
-        else if (tok->str() == "__null" || tok->str() == "'\\0'" || tok->str() == "'\\x0'") {
+        else if (tok->str() == "__null") {
             tok->originalName(tok->str());
             tok->str("0");
         }
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index fb376d214..890a03ae4 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -341,7 +341,7 @@ private:
         ASSERT_EQUALS("; x [ ++ y ] = x [ y ] + 1 ;", tok("; x[++y] += 1;"));
 
         ASSERT_EQUALS(";", tok(";x += 0;"));
-        ASSERT_EQUALS(";", tok(";x += '\\0';"));
+        TODO_ASSERT_EQUALS(";", "; x = x + '\\0' ;", tok("; x += '\\0'; "));
         ASSERT_EQUALS(";", tok(";x -= 0;"));
         ASSERT_EQUALS(";", tok(";x |= 0;"));
         ASSERT_EQUALS(";", tok(";x *= 1;"));
diff --git a/test/testtokenize.cpp b/test/testtokenize.cpp
index ffdcebb2a..ff84a2498 100644
--- a/test/testtokenize.cpp
+++ b/test/testtokenize.cpp
@@ -3698,15 +3698,13 @@ private:
     void vardecl8() {
         // ticket #696
         const char code[] = "char a[10]={'\\0'}, b[10]={'\\0'};";
-        const char res[]  = "char a [ 10 ] = { 0 } ; char b [ 10 ] = { 0 } ;";
-
+        const char res[]  = "char a [ 10 ] = { '\\0' } ; char b [ 10 ] = { '\\0' } ;";
         ASSERT_EQUALS(res, tokenizeAndStringify(code));
     }
 
     void vardecl9() {
         const char code[] = "char a[2] = {'A', '\\0'}, b[2] = {'B', '\\0'};";
-        const char res[]  = "char a [ 2 ] = { 'A' , 0 } ; char b [ 2 ] = { 'B' , 0 } ;";
-
+        const char res[]  = "char a [ 2 ] = { 'A' , '\\0' } ; char b [ 2 ] = { 'B' , '\\0' } ;";
         ASSERT_EQUALS(res, tokenizeAndStringify(code));
     }