diff --git a/lib/token.cpp b/lib/token.cpp
index f92742d61..89d9bf0c5 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -175,6 +175,9 @@ void Token::concatStr(std::string const& b)
     mStr.erase(mStr.length() - 1);
     mStr.append(getStringLiteral(b) + "\"");
 
+    if (isCChar() && isStringLiteral(b) && b[0] != '"') {
+        mStr.insert(0, b.substr(0, b.find('"')));
+    }
     update_property_info();
 }
 
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index 2cf3747e7..4327081f3 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -90,7 +90,14 @@ private:
 
         TEST_CASE(cast);
         TEST_CASE(iftruefalse);
+
         TEST_CASE(combine_strings);
+        TEST_CASE(combine_wstrings);
+        TEST_CASE(combine_ustrings);
+        TEST_CASE(combine_Ustrings);
+        TEST_CASE(combine_u8strings);
+        TEST_CASE(combine_mixedstrings);
+
         TEST_CASE(double_plus);
         TEST_CASE(redundant_plus);
         TEST_CASE(redundant_plus_numbers);
@@ -143,11 +150,6 @@ private:
         TEST_CASE(doWhileAssign); // varid
         TEST_CASE(test_4881); // similar to doWhileAssign (#4911), taken from #4881 with full code
 
-        TEST_CASE(combine_wstrings);
-        TEST_CASE(combine_ustrings);
-        TEST_CASE(combine_Ustrings);
-        TEST_CASE(combine_u8strings);
-
         // Simplify "not" to "!" (#345)
         TEST_CASE(not1);
 
@@ -1811,7 +1813,6 @@ private:
         tokenizer.tokenize(istr, "test.cpp");
 
         ASSERT_EQUALS(expected, tokenizer.tokens()->stringifyList(nullptr, false));
-        ASSERT_EQUALS(true, tokenizer.tokens()->tokAt(2)->isLong());
     }
 
     void combine_ustrings() {
@@ -1824,7 +1825,6 @@ private:
         tokenizer.tokenize(istr, "test.cpp");
 
         ASSERT_EQUALS(expected, tokenizer.tokens()->stringifyList(nullptr, false));
-        ASSERT_EQUALS(false, tokenizer.tokens()->tokAt(2)->isLong());
     }
 
     void combine_Ustrings() {
@@ -1837,7 +1837,6 @@ private:
         tokenizer.tokenize(istr, "test.cpp");
 
         ASSERT_EQUALS(expected, tokenizer.tokens()->stringifyList(nullptr, false));
-        ASSERT_EQUALS(false, tokenizer.tokens()->tokAt(2)->isLong());
     }
 
     void combine_u8strings() {
@@ -1845,13 +1844,23 @@ private:
 
         const char expected[] =  "abcd = u8\"abcd\" ;";
 
+        Tokenizer tokenizer(&settings0, this);
+        std::istringstream istr(code);
+        tokenizer.tokenize(istr, "test.cpp");
+
+        ASSERT_EQUALS(expected, tokenizer.tokens()->stringifyList(nullptr, false));
+    }
+
+    void combine_mixedstrings() {
+        const char code[] = "abcdef = \"ab\" L\"cd\" \"ef\";";
+
+        const char expected[] =  "abcdef = L\"abcdef\" ;";
 
         Tokenizer tokenizer(&settings0, this);
         std::istringstream istr(code);
         tokenizer.tokenize(istr, "test.cpp");
 
         ASSERT_EQUALS(expected, tokenizer.tokens()->stringifyList(nullptr, false));
-        ASSERT_EQUALS(false, tokenizer.tokens()->tokAt(2)->isLong());
     }
 
     void double_plus() {
diff --git a/test/testtoken.cpp b/test/testtoken.cpp
index e2ef5a75f..37c0768c3 100644
--- a/test/testtoken.cpp
+++ b/test/testtoken.cpp
@@ -62,6 +62,7 @@ private:
         TEST_CASE(getStrSize);
         TEST_CASE(getCharAt);
         TEST_CASE(strValue);
+        TEST_CASE(concatStr);
 
         TEST_CASE(deleteLast);
         TEST_CASE(deleteFirst);
@@ -92,7 +93,6 @@ private:
         TEST_CASE(operators);
 
         TEST_CASE(updateProperties)
-        TEST_CASE(updatePropertiesConcatStr)
         TEST_CASE(isNameGuarantees1)
         TEST_CASE(isNameGuarantees2)
         TEST_CASE(isNameGuarantees3)
@@ -462,6 +462,44 @@ private:
         ASSERT_EQUALS("a", tok.strValue());
     }
 
+    void concatStr() const {
+        Token tok;
+
+        tok.str("\"\"");
+        tok.concatStr("\"\"");
+        ASSERT_EQUALS("", tok.strValue());
+        ASSERT(tok.isCChar());
+
+        tok.str("\"ab\"");
+        tok.concatStr("\"cd\"");
+        ASSERT_EQUALS("abcd", tok.strValue());
+        ASSERT(tok.isCChar());
+
+        tok.str("L\"ab\"");
+        tok.concatStr("L\"cd\"");
+        ASSERT_EQUALS("abcd", tok.strValue());
+        ASSERT(tok.isLong());
+
+        tok.str("L\"ab\"");
+        tok.concatStr("\"cd\"");
+        ASSERT_EQUALS("abcd", tok.strValue());
+        ASSERT(tok.isLong());
+
+        tok.str("\"ab\"");
+        tok.concatStr("L\"cd\"");
+        ASSERT_EQUALS("abcd", tok.strValue());
+        ASSERT(tok.isLong());
+
+        tok.str("\"ab\"");
+        tok.concatStr("L\"\"");
+        ASSERT_EQUALS("ab", tok.strValue());
+        ASSERT(tok.isLong());
+
+        tok.str("\"ab\"");
+        tok.concatStr("u8\"cd\"");
+        ASSERT_EQUALS("abcd", tok.strValue());
+        ASSERT(tok.isUtf8());
+    }
 
     void deleteLast() const {
         TokensFrontBack listEnds{ nullptr };
@@ -977,18 +1015,6 @@ private:
         ASSERT_EQUALS(true, tok.isNumber());
     }
 
-    void updatePropertiesConcatStr() const {
-        Token tok;
-        tok.str("true");
-
-        ASSERT_EQUALS(true, tok.isBoolean());
-
-        tok.concatStr("123");
-
-        ASSERT_EQUALS(false, tok.isBoolean());
-        ASSERT_EQUALS("tru\"", tok.str());
-    }
-
     void isNameGuarantees1() const {
         Token tok;
         tok.str("Name");