diff --git a/lib/checkio.cpp b/lib/checkio.cpp
index 6a8475af7..c42273f3c 100644
--- a/lib/checkio.cpp
+++ b/lib/checkio.cpp
@@ -448,7 +448,7 @@ void CheckIO::checkWrongPrintfScanfArguments()
                 } else {
                     continue;
                 }
-            } else if (Token::Match(tok, "sprintf|fprintf|sscanf|fscanf|swscanf|fwprintf|fwscanf ( %any%")) {
+            } else if (Token::Match(tok, "sprintf|fprintf|sscanf|fscanf|swscanf|fwprintf|fwscanf ( %any%") || (Token::simpleMatch(tok, "swprintf (") && Token::Match(tok->tokAt(2)->nextArgument(), "%str%"))) {
                 const Token* formatStringTok = tok->tokAt(2)->nextArgument(); // Find second parameter (format string)
                 if (Token::Match(formatStringTok, "%str% ,")) {
                     argListTok = formatStringTok->nextArgument(); // Find third parameter (first argument of va_args)
@@ -459,7 +459,7 @@ void CheckIO::checkWrongPrintfScanfArguments()
                 } else {
                     continue;
                 }
-            } else if (Token::Match(tok, "snprintf|fnprintf|swprintf (")) {
+            } else if (Token::Match(tok, "snprintf|fnprintf (") || (Token::simpleMatch(tok, "swprintf (") && !Token::Match(tok->tokAt(2)->nextArgument(), "%str%"))) {
                 const Token* formatStringTok = tok->tokAt(2);
                 for (int i = 0; i < 2 && formatStringTok; i++) {
                     formatStringTok = formatStringTok->nextArgument(); // Find third parameter (format string)
diff --git a/test/testio.cpp b/test/testio.cpp
index 8377989da..0aa286210 100644
--- a/test/testio.cpp
+++ b/test/testio.cpp
@@ -577,6 +577,15 @@ private:
                       "[test.cpp:3]: (warning) printf format string has 1 parameters but 2 are given.\n"
                       "[test.cpp:4]: (warning) printf format string has 2 parameters but 3 are given.\n", errout.str());
 
+        check("void foo() {\n" // swprintf exists as MSVC extension and as standard function: #4790
+              "    swprintf(string1, L\"%u\", 32, string2);\n" // MSVC implementation
+              "    swprintf(string1, L\"%s%s\", L\"a\", string2);\n" // MSVC implementation
+              "    swprintf(string1, 6, L\"%u\", 32, string2);\n" // Standard implementation
+              "    swprintf(string1, 6, L\"%u%s\", 32, string2);\n" // Standard implementation
+              "}");
+        ASSERT_EQUALS("[test.cpp:2]: (warning) swprintf format string has 1 parameters but 2 are given.\n"
+                      "[test.cpp:4]: (warning) swprintf format string has 1 parameters but 2 are given.\n", errout.str());
+
         check("void foo(char *str) {\n"
               "    printf(\"%u\", 0);\n"
               "    printf(\"%u%s\", 123, bar());\n"
diff --git a/test/testsymboldatabase.cpp b/test/testsymboldatabase.cpp
index 850c6fd46..af802e249 100644
--- a/test/testsymboldatabase.cpp
+++ b/test/testsymboldatabase.cpp
@@ -539,7 +539,7 @@ private:
         ASSERT(false == v.isPointer());
         ASSERT(true == v.isReference());
         ASSERT(true == v.isRValueReference());
-        ASSERT(var.tokens()->tokAt(2)->scope());
+        ASSERT(var.tokens()->tokAt(2)->scope() != 0);
     }
 
     void staticMemberVar() {