diff --git a/features/netsocket/TCPServer.cpp b/features/netsocket/TCPServer.cpp
index 85f3249341..b0fe5acda1 100644
--- a/features/netsocket/TCPServer.cpp
+++ b/features/netsocket/TCPServer.cpp
@@ -18,7 +18,7 @@
 #include "mbed.h"
 
 TCPServer::TCPServer()
-    : _pending(0), _accept_sem(0)
+    : _pending(1), _accept_sem(0)
 {
 }
 
diff --git a/features/netsocket/TCPServer.h b/features/netsocket/TCPServer.h
index 6c26e2c707..2e5b5ab573 100644
--- a/features/netsocket/TCPServer.h
+++ b/features/netsocket/TCPServer.h
@@ -46,7 +46,7 @@ public:
      */
     template <typename S>
     TCPServer(S *stack)
-        : _pending(0), _accept_sem(0)
+        : _pending(1), _accept_sem(0)
     {
         open(stack);
     }
diff --git a/features/netsocket/TCPSocket.cpp b/features/netsocket/TCPSocket.cpp
index 010dd7d039..230c1c297d 100644
--- a/features/netsocket/TCPSocket.cpp
+++ b/features/netsocket/TCPSocket.cpp
@@ -19,7 +19,7 @@
 #include "mbed_assert.h"
 
 TCPSocket::TCPSocket()
-    : _pending(0), _read_sem(0), _write_sem(0),
+    : _pending(1), _read_sem(0), _write_sem(0),
       _read_in_progress(false), _write_in_progress(false)
 {
 }
diff --git a/features/netsocket/TCPSocket.h b/features/netsocket/TCPSocket.h
index b8a41eea71..cd554682a5 100644
--- a/features/netsocket/TCPSocket.h
+++ b/features/netsocket/TCPSocket.h
@@ -45,7 +45,7 @@ public:
      */
     template <typename S>
     TCPSocket(S *stack)
-        : _pending(0), _read_sem(0), _write_sem(0),
+        : _pending(1), _read_sem(0), _write_sem(0),
           _read_in_progress(false), _write_in_progress(false)
     {
         open(stack);
diff --git a/features/netsocket/UDPSocket.cpp b/features/netsocket/UDPSocket.cpp
index 08f270cdd8..654142eee7 100644
--- a/features/netsocket/UDPSocket.cpp
+++ b/features/netsocket/UDPSocket.cpp
@@ -19,7 +19,7 @@
 #include "mbed_assert.h"
 
 UDPSocket::UDPSocket()
-    : _pending(0), _read_sem(0), _write_sem(0)
+    : _pending(1), _read_sem(0), _write_sem(0)
 {
 }
 
diff --git a/features/netsocket/UDPSocket.h b/features/netsocket/UDPSocket.h
index 9cc2d5d8e4..d6000d83a2 100644
--- a/features/netsocket/UDPSocket.h
+++ b/features/netsocket/UDPSocket.h
@@ -45,7 +45,7 @@ public:
      */
     template <typename S>
     UDPSocket(S *stack)
-        : _pending(0), _read_sem(0), _write_sem(0)
+        : _pending(1), _read_sem(0), _write_sem(0)
     {
         open(stack);
     }
diff --git a/tools/toolchains/__init__.py b/tools/toolchains/__init__.py
index ce0ee7cd3b..6a15fc6cee 100644
--- a/tools/toolchains/__init__.py
+++ b/tools/toolchains/__init__.py
@@ -472,7 +472,7 @@ class mbedToolchain:
 
             # This is a policy decision and it should /really/ be in the config system
             # ATM it's here for backward compatibility
-            if (("-g" in self.flags['common'] and
+            if ((("-g" in self.flags['common'] or "-g3" in self.flags['common']) and
                  "-O0") in self.flags['common'] or
                 ("-r" in self.flags['common'] and
                  "-On" in self.flags['common'])):