diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index d5f369496..9fa1597f4 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -5279,7 +5279,6 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
       <not-null/>
       <not-uninit/>
       <minsize type="argvalue" arg="2"/>
-      <strz/>
     </arg>
     <arg nr="2" direction="in">
       <not-uninit/>
diff --git a/cfg/std.cfg b/cfg/std.cfg
index 566f7104c..c7633313a 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -5209,7 +5209,6 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
     <leak-ignore/>
     <!-- In case the 3rd argument is 0, the 1st argument is permitted to be a null pointer. (#6306) -->
     <arg nr="1" direction="out">
-      <strz/>
       <minsize type="argvalue" arg="3"/>
     </arg>
     <arg nr="2" direction="in">
diff --git a/lib/checkfunctions.cpp b/lib/checkfunctions.cpp
index 75538c309..1d6ce74b9 100644
--- a/lib/checkfunctions.cpp
+++ b/lib/checkfunctions.cpp
@@ -141,7 +141,7 @@ void CheckFunctions::invalidFunctionUsage()
                     const Variable* const variable = argtok->variable();
                     // Is non-null terminated local variable of type char (e.g. char buf[] = {'x'};) ?
                     if (variable && variable->isLocal()
-                        && valueType && valueType->type == ValueType::Type::CHAR) {
+                        && valueType && (valueType->type == ValueType::Type::CHAR || valueType->type == ValueType::Type::WCHAR_T)) {
                         const Token* varTok = variable->declEndToken();
                         auto count = -1; // Find out explicitly set count, e.g.: char buf[3] = {...}. Variable 'count' is set to 3 then.
                         if (varTok && Token::simpleMatch(varTok->previous(), "]"))
@@ -170,6 +170,13 @@ void CheckFunctions::invalidFunctionUsage()
                                 && (count == -1 || (count > 0 && count <= charsUntilFirstZero))) {
                                 invalidFunctionArgStrError(argtok, functionToken->str(), argnr);
                             }
+                        } else if (count > -1 && Token::Match(varTok, "= %str%")) {
+                            const Token* strTok = varTok->getValueTokenMinStrSize(mSettings);
+                            if (strTok) {
+                                const int strSize = Token::getStrArraySize(strTok);
+                                if (strSize > count)
+                                    invalidFunctionArgStrError(argtok, functionToken->str(), argnr);
+                            }
                         }
                     }
                 }
diff --git a/test/cfg/posix.c b/test/cfg/posix.c
index d45cc26f2..aad6217ee 100644
--- a/test/cfg/posix.c
+++ b/test/cfg/posix.c
@@ -558,9 +558,7 @@ void bufferAccessOutOfBounds_bzero(void *s, size_t n)
 size_t bufferAccessOutOfBounds_strnlen(const char *s, size_t maxlen)
 {
     const char buf[2]={'4','2'};
-    // cppcheck-suppress invalidFunctionArgStr
     size_t len = strnlen(buf,2);
-    // cppcheck-suppress invalidFunctionArgStr
     // cppcheck-suppress bufferAccessOutOfBounds
     len+=strnlen(buf,3);
     return len;
diff --git a/test/cfg/std.c b/test/cfg/std.c
index 873adef83..684c4dd7a 100644
--- a/test/cfg/std.c
+++ b/test/cfg/std.c
@@ -34,7 +34,7 @@ size_t invalidFunctionArgStr_wcslen(void)
     const wchar_t terminated0[] = L"ABCDEF49620910";
     const wchar_t terminated1[3] = { L'a', L'b', L'\0' };
     const wchar_t notTerminated[3] = { L'a', L'b', L'c' };
-    // TODO: cppcheck-suppress invalidFunctionArgStr
+    // cppcheck-suppress invalidFunctionArgStr
     (void) wcslen(notTerminated);
     (void) wcslen(terminated0);
     return wcslen(terminated1);
@@ -3908,10 +3908,11 @@ void bufferAccessOutOfBounds_strxfrm(void)
 {
     const char src[3] = "abc";
     char dest[1] = "a";
+    // cppcheck-suppress invalidFunctionArgStr
     (void)strxfrm(dest,src,1);
-    // cppcheck-suppress bufferAccessOutOfBounds
+    // cppcheck-suppress [bufferAccessOutOfBounds,invalidFunctionArgStr]
     (void)strxfrm(dest,src,2);
-    // cppcheck-suppress bufferAccessOutOfBounds
+    // cppcheck-suppress [bufferAccessOutOfBounds,invalidFunctionArgStr]
     (void)strxfrm(dest,src,3);
 }
 
diff --git a/test/testfunctions.cpp b/test/testfunctions.cpp
index e95c0fc8c..33d05ff82 100644
--- a/test/testfunctions.cpp
+++ b/test/testfunctions.cpp
@@ -711,6 +711,18 @@ private:
               "    }\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        check("int f() {\n"
+              "    const char c[3] = \"abc\";\n"
+              "    return strlen(c);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3]: (error) Invalid strlen() argument nr 1. A nul-terminated string is required.\n", errout.str());
+
+        check("int f() {\n"
+              "    const wchar_t c[3] = L\"abc\";\n"
+              "    return wcslen(c);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3]: (error) Invalid wcslen() argument nr 1. A nul-terminated string is required.\n", errout.str());
     }
 
     void mathfunctionCall_sqrt() {