diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 19c881e7ba5..d67356ad086 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -3774,7 +3774,8 @@ void Tokenizer::concatenateNegativeNumberAndAnyPositive()
         if (!tok->tokAt(2) || (tok->tokAt(2)->isOp() && !Token::Match(tok->tokAt(2), "[+-*]")))
             syntaxError(tok);
 
-        while (tok->str() != ">" && tok->next() && tok->strAt(1) == "+" && (!Token::Match(tok->tokAt(2), "%name% (|;") || Token::Match(tok, "%op%")))
+        while ((tok->isArithmeticalOp() || tok->isComparisonOp()) && tok->str() != ">" && tok->next() && tok->strAt(1) == "+" &&
+               (!Token::Match(tok->tokAt(2), "%name% (|;") || Token::Match(tok, "%op%")))
             tok->deleteNext();
 
         if (Token::Match(tok->next(), "+|- %num%")) {
diff --git a/test/testsymboldatabase.cpp b/test/testsymboldatabase.cpp
index dfb61665b8a..cbd9eafb8d3 100644
--- a/test/testsymboldatabase.cpp
+++ b/test/testsymboldatabase.cpp
@@ -546,6 +546,7 @@ class TestSymbolDatabase : public TestFixture {
         TEST_CASE(findFunction62); // #14272 - pointer passed to function is const
         TEST_CASE(findFunction63); // #14937 - member function of type returned by operator()
         TEST_CASE(findFunction64); // overloaded operator()
+        TEST_CASE(findFunction65);
         TEST_CASE(findFunctionRef1);
         TEST_CASE(findFunctionRef2); // #13328
         TEST_CASE(findFunctionContainer);
@@ -8990,6 +8991,20 @@ class TestSymbolDatabase : public TestFixture {
         }
     }
 
+    void findFunction65()
+    {
+        {
+            GET_SYMBOL_DB("bool g(char) { return true; }\n" // #15033
+                          "bool g(int) { return false; }\n"
+                          "void f(char c) {\n"
+                          "    if (g(+c)) {}\n"
+                          "}\n");
+            const Token* g = Token::findsimplematch(tokenizer.tokens(), "g ( +");
+            ASSERT(g && g->function());
+            ASSERT_EQUALS(2, g->function()->tokenDef->linenr());
+        }
+    }
+
     void findFunctionRef1() {
         GET_SYMBOL_DB("struct X {\n"
                       "    const std::vector<int> getInts() const & { return mInts; }\n"
diff --git a/test/testtokenize.cpp b/test/testtokenize.cpp
index 7a07516b632..a25ea9c4bd6 100644
--- a/test/testtokenize.cpp
+++ b/test/testtokenize.cpp
@@ -1104,7 +1104,7 @@ class TestTokenizer : public TestFixture {
         ASSERT_EQUALS("int f ( ) { return -2 ; }", tokenizeAndStringify("int f(){return -2;}\n"));
         ASSERT_EQUALS("int x [ 2 ] = { -2 , 1 }", tokenizeAndStringify("int x[2] = {-2,1}\n"));
 
-        ASSERT_EQUALS("f ( 123 )", tokenizeAndStringify("f(+123)\n"));
+        ASSERT_EQUALS("f ( +123 )", tokenizeAndStringify("f(+123)\n"));
 
         ASSERT_EQUALS("std :: extent_v < A > - 1 ;", tokenizeAndStringify("std::extent_v<A> - 1;\n")); // #11341
     }
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 618e16624d8..301937718f4 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -1837,6 +1837,14 @@ class TestValueFlow : public TestFixture {
         ASSERT_EQUALS(1U, values.size());
         ASSERT_EQUALS(3 * settings.platform.sizeof_int, values.back().intvalue);
         ASSERT_EQUALS_ENUM(ValueFlow::Value::ValueKind::Known, values.back().valueKind);
+
+        code = "int f(char c) {\n" // #15033
+               "    return sizeof(+c);\n"
+               "}\n";
+        values = tokenValues(code, "( +");
+        ASSERT_EQUALS(1U, values.size());
+        ASSERT_EQUALS(settings.platform.sizeof_int, values.back().intvalue);
+        ASSERT_EQUALS_ENUM(ValueFlow::Value::ValueKind::Known, values.back().valueKind);
     }
 
     void valueFlowComma()