diff --git a/cfg/std.cfg b/cfg/std.cfg
index 77117b0bd..d980b9270 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -943,6 +943,26 @@
       <not-uninit/>
     </arg>
   </function>
+  <!-- errno_t fopen_s(FILE *restrict *restrict streamptr,
+                const char *restrict filename,
+                const char *restrict mode); -->
+  <function name="fopen_s">
+    <use-retval/>
+    <noreturn>false</noreturn>
+    <arg nr="1">
+      <not-null/>
+      <not-uninit/>
+      <strz/>
+    </arg>
+    <arg nr="2">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+    <arg nr="3">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+  </function>
   <!-- int fprintf(FILE *stream, const char *format, ...); -->
   <function name="fprintf,std::fprintf">
     <noreturn>false</noreturn>
@@ -3996,6 +4016,7 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
   </memory>
   <resource>
     <alloc init="true">fopen</alloc>
+    <alloc init="true">fopen_s</alloc>
     <alloc init="true">tmpfile</alloc>
     <dealloc>fclose</dealloc>
   </resource>
diff --git a/cfg/windows.cfg b/cfg/windows.cfg
index 8a0eb8e6e..5716f4bbc 100644
--- a/cfg/windows.cfg
+++ b/cfg/windows.cfg
@@ -985,6 +985,8 @@
   <resource>
     <alloc init="true">_wfopen</alloc>
     <alloc init="true">_tfopen</alloc>
+    <alloc init="true">_wfopen_s</alloc>
+    <alloc init="true">_tfopen_s</alloc>
     <dealloc>fclose</dealloc>
   </resource>
   <memory>
@@ -1741,6 +1743,47 @@
       <not-uninit/>
     </arg>
   </function>
+  <!-- int sprintf_s(char *buffer, size_t sizeOfBuffer, const char *format, ... ); 
+       int swprintf_s(wchar_t *buffer, size_t sizeOfBuffer, const wchar_t *format, ...);-->
+  <function name="sprintf_s,swprintf_s">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <arg nr="1">
+      <minsize type="argvalue" arg="2"/>
+    </arg>
+    <arg nr="2">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+    <formatstr/>
+    <arg nr="3">
+      <formatstr/>
+      <not-null/>
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- int _sprintf_s_l(char *buffer, size_t sizeOfBuffer, const char *format, locale_t locale, ... ); 
+       int _swprintf_s_l(wchar_t *buffer, size_t sizeOfBuffer, const wchar_t *format, locale_t locale, ...);-->
+  <function name="_sprintf_s_l,_swprintf_s_l">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <arg nr="1">
+      <minsize type="argvalue" arg="2"/>
+    </arg>
+    <arg nr="2">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+    <formatstr/>
+    <arg nr="3">
+      <formatstr/>
+      <not-null/>
+      <not-uninit/>
+    </arg>
+    <arg nr="4">
+      <not-uninit/>
+    </arg>
+  </function>
   <!-- LONG WINAPI RegEnumKeyEx(
   _In_        HKEY      hKey,
   _In_        DWORD     dwIndex,
@@ -2047,4 +2090,22 @@ HFONT CreateFont(
       <not-uninit/>
     </arg>
   </function>
+  <!-- errno_t _wfopen_s(FILE** pFile, const wchar_t *filename, const wchar_t *mode); -->
+  <function name="_wfopen_s,_tfopen_s">
+    <use-retval/>
+    <noreturn>false</noreturn>
+    <arg nr="1">
+      <not-null/>
+      <not-uninit/>
+      <strz/>
+    </arg>
+    <arg nr="2">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+    <arg nr="3">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+  </function>
 </def>
diff --git a/test/testio.cpp b/test/testio.cpp
index 59a8ea2b8..1f13eb7f4 100644
--- a/test/testio.cpp
+++ b/test/testio.cpp
@@ -2563,7 +2563,7 @@ private:
         check("void foo() {\n"
               "    char lineBuffer [600];\n"
               "    const char * const format = \"%15s%17s%17s%17s%17s\n\";\n"
-              "    sprintf_s(lineBuffer, format, \"type\", \"sum\", \"avg\", \"min\", \"max\");\n"
+              "    sprintf_s(lineBuffer, 600, format, \"type\", \"sum\", \"avg\", \"min\", \"max\");\n"
               "}\n", false, false, Settings::Win32A);
         ASSERT_EQUALS("", errout.str());
 
@@ -2572,9 +2572,9 @@ private:
               "    const char format2[] = \"%15s%17s%17s%17s%17s\n\";\n"
               "    const char * const format3 = format1;\n"
               "    int i = 0;\n"
-              "    sprintf_s(lineBuffer, format1, \"type\", \"sum\", \"avg\", \"min\", i, 0);\n"
-              "    sprintf_s(lineBuffer, format2, \"type\", \"sum\", \"avg\", \"min\", i, 0);\n"
-              "    sprintf_s(lineBuffer, format3, \"type\", \"sum\", \"avg\", \"min\", i, 0);\n"
+              "    sprintf_s(lineBuffer, 100, format1, \"type\", \"sum\", \"avg\", \"min\", i, 0);\n"
+              "    sprintf_s(lineBuffer, 100, format2, \"type\", \"sum\", \"avg\", \"min\", i, 0);\n"
+              "    sprintf_s(lineBuffer, 100, format3, \"type\", \"sum\", \"avg\", \"min\", i, 0);\n"
               "    sprintf(lineBuffer, format1, \"type\", \"sum\", \"avg\", \"min\", i, 0);\n"
               "    sprintf(lineBuffer, format2, \"type\", \"sum\", \"avg\", \"min\", i, 0);\n"
               "    sprintf(lineBuffer, format3, \"type\", \"sum\", \"avg\", \"min\", i, 0);\n"