diff --git a/cfg/std.cfg b/cfg/std.cfg
index f704dafc0..ea6be2cc7 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -6813,6 +6813,7 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
     </arg>
     <arg nr="2" default="0" direction="in">
       <not-uninit/>
+      <valid>0:</valid>
     </arg>
   </function>
   <function name="std::wstring::substr">
@@ -6825,6 +6826,7 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
     </arg>
     <arg nr="2" default="0" direction="in">
       <not-uninit/>
+      <valid>0:</valid>
     </arg>
   </function>
   <function name="std::basic_string::substr">
@@ -6837,6 +6839,7 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
     </arg>
     <arg nr="2" default="0" direction="in">
       <not-uninit/>
+      <valid>0:</valid>
     </arg>
   </function>
   <!-- void std::ios::clear (std::ios::iostate state = std::ios::goodbit);-->
diff --git a/test/cfg/std.cpp b/test/cfg/std.cpp
index 3e06bd92a..84f0a37e7 100644
--- a/test/cfg/std.cpp
+++ b/test/cfg/std.cpp
@@ -31,6 +31,26 @@
 #include <iterator>
 #include <vector>
 
+void invalidFunctionArg_std_string_substr(const std::string &str, std::size_t pos, std::size_t len) {
+    // cppcheck-suppress invalidFunctionArg
+    (void)str.substr(-1,len);
+    // cppcheck-suppress invalidFunctionArg
+    (void)str.substr(pos,-1);
+    // no warning is expected for
+    (void)str.substr(pos,len);
+    (void)str.substr(pos, std::wstring::npos);
+}
+
+void invalidFunctionArg_std_wstring_substr(const std::wstring &str, std::size_t pos, std::size_t len) {
+    // cppcheck-suppress invalidFunctionArg
+    (void)str.substr(-1,len);
+    // cppcheck-suppress invalidFunctionArg
+    (void)str.substr(pos,-1);
+    // no warning is expected for
+    (void)str.substr(pos,len);
+    (void)str.substr(pos, std::string::npos);
+}
+
 double invalidFunctionArg_log10(double d = 0.0) {
     // cppcheck-suppress invalidFunctionArg
     return log10(d);