diff --git a/src/include/lwip/dhcp.h b/src/include/lwip/dhcp.h
index c78aa0ba..3495feb9 100644
--- a/src/include/lwip/dhcp.h
+++ b/src/include/lwip/dhcp.h
@@ -54,7 +54,7 @@ extern "C" {
 /** period (in milliseconds) of the application calling dhcp_coarse_tmr() */
 #define DHCP_COARSE_TIMER_MSECS (DHCP_COARSE_TIMER_SECS * 1000UL)
 /** period (in milliseconds) of the application calling dhcp_fine_tmr() */
-#define DHCP_FINE_TIMER_MSECS   500
+#define DHCP_FINE_TIMER_MSECS   100
 
 #define DHCP_BOOT_FILE_LEN      128U
 
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index d8c82d15..4713fef0 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -828,6 +828,14 @@
 #if !defined IP_FORWARD_ALLOW_TX_ON_RX_NETIF || defined __DOXYGEN__
 #define IP_FORWARD_ALLOW_TX_ON_RX_NETIF 0
 #endif
+/**
+ * LWIP_RANDOMIZE_INITIAL_LOCAL_PORTS==1: randomize the local port for the first
+ * local TCP/UDP pcb (default==0). This can prevent creating predictable port
+ * numbers after booting a device.
+ */
+#if !defined LWIP_RANDOMIZE_INITIAL_LOCAL_PORTS || defined __DOXYGEN__
+#define LWIP_RANDOMIZE_INITIAL_LOCAL_PORTS 1
+#endif
 /**
  * @}
  */
diff --git a/src/include/lwip/sockets.h b/src/include/lwip/sockets.h
index d70d36c4..00143f99 100644
--- a/src/include/lwip/sockets.h
+++ b/src/include/lwip/sockets.h
@@ -515,7 +515,7 @@ struct pollfd
 /** LWIP_TIMEVAL_PRIVATE: if you want to use the struct timeval provided
  * by your system, set this to 0 and include <sys/time.h> in cc.h */
 #ifndef LWIP_TIMEVAL_PRIVATE
-#define LWIP_TIMEVAL_PRIVATE 1
+#define LWIP_TIMEVAL_PRIVATE 0
 #endif
 
 #if LWIP_TIMEVAL_PRIVATE