diff --git a/cfg/std.cfg b/cfg/std.cfg
index f93c5e0ed..cd024c437 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -8004,6 +8004,7 @@ initializer list (7) string& replace (const_iterator i1, const_iterator i2, init
     <returnValue type="void"/>
     <leak-ignore/>
     <arg nr="1" direction="in">
+      <not-null/>
       <not-uninit/>
       <not-bool/>
     </arg>
diff --git a/test/cfg/std.c b/test/cfg/std.c
index d5f5adc66..9637f322f 100644
--- a/test/cfg/std.c
+++ b/test/cfg/std.c
@@ -23,6 +23,7 @@
 #include <time.h>
 #include <stdbool.h>
 #include <stdint.h>
+#include <threads.h>
 #include <inttypes.h>
 #include <float.h>
 
@@ -4363,6 +4364,15 @@ void nullPointer_system(char *c)
     (void)system(c);
 }
 
+int nullPointer_mtx_timedlock( mtx_t *restrict mutex, const struct timespec *restrict time_point )
+{
+    // cppcheck-suppress nullPointer
+    (void) mtx_timedlock(NULL, time_point);
+    // cppcheck-suppress nullPointer
+    (void) mtx_timedlock(mutex, NULL);
+    return mtx_timedlock(mutex, time_point);
+}
+
 void uninitvar_zonetime(void)
 {
     time_t *tp;
diff --git a/test/cfg/std.cpp b/test/cfg/std.cpp
index 56ea2bddc..5f10bdeb1 100644
--- a/test/cfg/std.cpp
+++ b/test/cfg/std.cpp
@@ -26,6 +26,7 @@
 #include <cwchar>
 #include <fstream>
 #include <functional>
+#include <threads.h>
 #include <iomanip>
 #include <ios>
 #include <iostream>
@@ -3660,6 +3661,36 @@ void uninitvar_system(void)
     (void)std::system(c);
 }
 
+void nullPointer_mtx_destroy( mtx_t *mutex )
+{
+    // cppcheck-suppress nullPointer
+    mtx_destroy(nullptr);
+    mtx_destroy(mutex);
+}
+
+void nullPointer_mtx_lock( mtx_t *mutex )
+{
+    // cppcheck-suppress nullPointer
+    mtx_lock(nullptr);
+    mtx_lock(mutex);
+}
+
+void nullPointer_mtx_trylock( mtx_t *mutex )
+{
+    // cppcheck-suppress nullPointer
+    mtx_trylock(nullptr);
+    mtx_trylock(mutex);
+}
+
+int nullPointer_mtx_timedlock( mtx_t *mutex, const struct timespec *time_point )
+{
+    // cppcheck-suppress nullPointer
+    (void) mtx_timedlock(nullptr, time_point);
+    // cppcheck-suppress nullPointer
+    (void) mtx_timedlock(mutex, nullptr);
+    return mtx_timedlock(mutex, time_point);
+}
+
 void nullPointer_system(char *c)
 {
     // If a null pointer is given, command processor is checked for existence