diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index c45217e3b..ed5a9a273 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -2928,6 +2928,56 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     </arg>
     <warn severity="style" reason="Obsolescent" alternatives="pthread_attr_getstack"/>
   </function>
+  <!-- int pthread_mutex_init(pthread_mutex_t *restrict mutex, const pthread_mutexattr_t *restrict attr); -->
+  <function name="pthread_mutex_init">
+    <noreturn>false</noreturn>
+    <returnValue type="int"/>
+    <arg nr="1">
+      <not-null/>
+    </arg>
+    <arg nr="2">
+      <!-- NULL is valid -->
+    </arg>
+  </function>
+  <!-- int pthread_mutex_destroy(pthread_mutex_t *mutex); -->
+  <function name="pthread_mutex_destroy">
+    <noreturn>false</noreturn>
+    <returnValue type="int"/>
+    <arg nr="1">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- int pthread_mutex_lock(pthread_mutex_t *mutex); -->
+  <function name="pthread_mutex_lock">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="int"/>
+    <arg nr="1">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- int pthread_mutex_trylock(pthread_mutex_t *mutex); -->
+  <function name="pthread_mutex_trylock">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="int"/>
+    <arg nr="1">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- int pthread_mutex_unlock(pthread_mutex_t *mutex); -->
+  <function name="pthread_mutex_unlock">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="int"/>
+    <arg nr="1">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+  </function>
   <!-- char *tempnam(const char *dir, const char *pfx); -->
   <function name="tempnam">
     <use-retval/>
diff --git a/test/cfg/posix.c b/test/cfg/posix.c
index 8a04de4ed..265c413e9 100644
--- a/test/cfg/posix.c
+++ b/test/cfg/posix.c
@@ -18,6 +18,7 @@
 #include <regex.h>
 #include <time.h>
 #include <unistd.h>
+#include <pthread.h>
 
 void bufferAccessOutOfBounds(int fd)
 {
@@ -54,7 +55,7 @@ void bufferAccessOutOfBounds(int fd)
     gethostname(a, 6);
 }
 
-void nullPointer(char *p, int fd)
+void nullPointer(char *p, int fd, pthread_mutex_t mutex)
 {
     // cppcheck-suppress ignoredReturnValue
     isatty(0);
@@ -88,6 +89,19 @@ void nullPointer(char *p, int fd)
     // cppcheck-suppress strtokCalled
     // cppcheck-suppress nullPointer
     strtok(p, NULL);
+
+    // cppcheck-suppress nullPointer
+    pthread_mutex_init(NULL, NULL);
+    // Second argument can be NULL
+    pthread_mutex_init(&mutex, NULL);
+    // cppcheck-suppress nullPointer
+    pthread_mutex_destroy(NULL);
+    // cppcheck-suppress nullPointer
+    pthread_mutex_lock(NULL);
+    // cppcheck-suppress nullPointer
+    pthread_mutex_trylock(NULL);
+    // cppcheck-suppress nullPointer
+    pthread_mutex_unlock(NULL);
 }
 
 void memleak_getaddrinfo()
@@ -207,6 +221,7 @@ void uninitvar(int fd)
     int decimal, sign;
     double d;
     void *p;
+    pthread_mutex_t mutex;
     // cppcheck-suppress uninitvar
     write(x,"ab",2);
     // TODO cppcheck-suppress uninitvar
@@ -259,6 +274,18 @@ void uninitvar(int fd)
     // cppcheck-suppress strtokCalled
     // cppcheck-suppress uninitvar
     strtok(strtok_arg1, ";");
+
+    // cppcheck-suppress uninitvar
+    pthread_mutex_lock(&mutex);
+    // cppcheck-suppress uninitvar
+    pthread_mutex_trylock(&mutex);
+    // cppcheck-suppress uninitvar
+    pthread_mutex_unlock(&mutex);
+    // after initialization it must be OK to call lock, trylock and unlock for this mutex
+    pthread_mutex_init(&mutex, NULL);
+    pthread_mutex_lock(&mutex);
+    pthread_mutex_trylock(&mutex);
+    pthread_mutex_unlock(&mutex);
 }
 
 void uninitvar_getcwd(void)