diff --git a/include/wx/msw/private/sockmsw.h b/include/wx/msw/private/sockmsw.h
index 70844e4742..d6010fbc1b 100644
--- a/include/wx/msw/private/sockmsw.h
+++ b/include/wx/msw/private/sockmsw.h
@@ -57,9 +57,6 @@ public:
         // anything here
     }
 
-private:
-    virtual void DoClose() wxOVERRIDE;
-
     virtual void UpdateBlockingState() wxOVERRIDE
     {
         if ( GetSocketFlags() & wxSOCKET_BLOCK )
@@ -86,6 +83,9 @@ private:
         }
     }
 
+private:
+    virtual void DoClose() wxOVERRIDE;
+
     int m_msgnumber;
 
     friend class wxSocketMSWManager;
diff --git a/include/wx/private/socket.h b/include/wx/private/socket.h
index 2d184acc07..20db91c7e7 100644
--- a/include/wx/private/socket.h
+++ b/include/wx/private/socket.h
@@ -281,6 +281,12 @@ public:
     // notifications
     // -------------
 
+    // Update the socket depending on the presence or absence of wxSOCKET_BLOCK
+    // in GetSocketFlags(): if it's present, make the socket blocking and
+    // ensure that we don't get any asynchronous event for it, otherwise put
+    // it into non-blocking mode and enable monitoring it in the event loop.
+    virtual void UpdateBlockingState() = 0;
+
     // notify m_wxsocket about the given socket event by calling its (inaptly
     // named) OnRequest() method
     void NotifyOnStateChange(wxSocketNotify event);
@@ -323,12 +329,6 @@ private:
     // called by Close() if we have a valid m_fd
     virtual void DoClose() = 0;
 
-    // Update the socket depending on the presence or absence of wxSOCKET_BLOCK
-    // in GetSocketFlags(): if it's present, make the socket blocking and
-    // ensure that we don't get any asynchronous event for it, otherwise put
-    // it into non-blocking mode and enable monitoring it in the event loop.
-    virtual void UpdateBlockingState() = 0;
-
     // check that the socket wasn't created yet and that the given address
     // (either m_local or m_peer depending on the socket kind) is valid and
     // set m_error and return false if this is not the case
diff --git a/include/wx/unix/private/sockunix.h b/include/wx/unix/private/sockunix.h
index 8b3fc2bbb0..f07ecafd87 100644
--- a/include/wx/unix/private/sockunix.h
+++ b/include/wx/unix/private/sockunix.h
@@ -59,6 +59,15 @@ public:
         EnableEvents(flags);
     }
 
+    virtual void UpdateBlockingState() wxOVERRIDE
+    {
+        // Make this int and not bool to allow passing it to ioctl().
+        const int isBlocking = (GetSocketFlags() & wxSOCKET_BLOCK) != 0;
+        ioctl(m_fd, FIONBIO, &isBlocking);
+
+        DoEnableEvents(wxSOCKET_INPUT_FLAG | wxSOCKET_OUTPUT_FLAG, !isBlocking);
+    }
+
     // wxFDIOHandler methods
     virtual void OnReadWaiting() wxOVERRIDE;
     virtual void OnWriteWaiting() wxOVERRIDE;
@@ -73,15 +82,6 @@ private:
         wxCloseSocket(m_fd);
     }
 
-    virtual void UpdateBlockingState() wxOVERRIDE
-    {
-        // Make this int and not bool to allow passing it to ioctl().
-        const int isBlocking = (GetSocketFlags() & wxSOCKET_BLOCK) != 0;
-        ioctl(m_fd, FIONBIO, &isBlocking);
-
-        DoEnableEvents(wxSOCKET_INPUT_FLAG | wxSOCKET_OUTPUT_FLAG, !isBlocking);
-    }
-
     // enable or disable notifications for socket input/output events
     void EnableEvents(int flags = wxSOCKET_INPUT_FLAG | wxSOCKET_OUTPUT_FLAG)
         { DoEnableEvents(flags, true); }
diff --git a/src/common/socket.cpp b/src/common/socket.cpp
index 3ae69fadd1..f6a5f57fa6 100644
--- a/src/common/socket.cpp
+++ b/src/common/socket.cpp
@@ -1672,7 +1672,20 @@ void wxSocketBase::SetFlags(wxSocketFlags flags)
                   "Using wxSOCKET_WAITALL or wxSOCKET_BLOCK with "
                   "wxSOCKET_NOWAIT doesn't make sense" );
 
+    // Blocking sockets are very different from non-blocking ones and we need
+    // to [un]register the socket with the event loop if wxSOCKET_BLOCK is
+    // being [un]set.
+    const bool
+        blockChanged = (m_flags & wxSOCKET_BLOCK) != (flags & wxSOCKET_BLOCK);
+
     m_flags = flags;
+
+    if ( blockChanged )
+    {
+        // Of course, we only do this if we already have the actual socket.
+        if ( m_impl )
+            m_impl->UpdateBlockingState();
+    }
 }