diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index 4af5564f3..fe86474e5 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -242,21 +242,10 @@
     </arg>
   </function>
   <!-- int open(const char *pathname, int flags) -->
-  <function name="open">
-    <use-retval/>
-    <returnValue type="int"/>
-    <noreturn>false</noreturn>
-    <arg nr="1">
-      <not-null/>
-      <not-uninit/>
-    </arg>
-    <arg nr="2">
-      <not-uninit/>
-    </arg>
-  </function>
   <!-- int open(const char *pathname, int flags, mode_t mode); -->
   <function name="open">
-    <use-retval/>
+    <!-- TODO: add use-retval when cppcheck suppresses redundant messages
+    because of violations to alloc/dealloc and use-retval configuration-->
     <returnValue type="int"/>
     <noreturn>false</noreturn>
     <arg nr="1">
@@ -266,7 +255,7 @@
     <arg nr="2">
       <not-uninit/>
     </arg>
-    <arg nr="3">
+    <arg nr="3" default="0">
       <not-uninit/>
     </arg>
   </function>
diff --git a/test/cfg/posix.c b/test/cfg/posix.c
index 40c8c9001..15227a160 100644
--- a/test/cfg/posix.c
+++ b/test/cfg/posix.c
@@ -62,6 +62,12 @@ void nullPointer(char *p, int fd)
     // not implemented yet: cppcheck-suppress nullPointer
     write(fd,NULL,42);
     write(fd,NULL,0);
+    // cppcheck-suppress leakReturnValNotUsed
+    // cppcheck-suppress nullPointer
+    open(NULL, 0);
+    // cppcheck-suppress leakReturnValNotUsed
+    // cppcheck-suppress nullPointer
+    open(NULL, 0, 0);
 }
 
 void memleak_getaddrinfo()
@@ -107,6 +113,20 @@ void resourceLeak_socket(void)
     // cppcheck-suppress resourceLeak
 }
 
+void resourceLeak_open1(void)
+{
+    // cppcheck-suppress unreadVariable
+    int fd = open("file", O_RDWR | O_CREAT);
+    // cppcheck-suppress resourceLeak   
+}
+
+void resourceLeak_open2(void)
+{
+    // cppcheck-suppress unreadVariable
+    int fd = open("file", O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+    // cppcheck-suppress resourceLeak   
+}
+
 void noleak(int x, int y, int z)
 {
     DIR *p1 = fdopendir(x);
@@ -115,6 +135,10 @@ void noleak(int x, int y, int z)
     closedir(p2);
     int s = socket(AF_INET,SOCK_STREAM,0);
     close(s);
+    int fd1 = open("a", O_RDWR | O_CREAT);
+    close(fd1);
+    int fd2 = open("a", O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+    close(fd2);
     /* TODO: add configuration for open/fdopen
         // #2830
         int fd = open("path", O_RDONLY);