diff --git a/drivers/net/dm90x0.c b/drivers/net/dm90x0.c
index feb7a70c722..7009e6f7ae7 100644
--- a/drivers/net/dm90x0.c
+++ b/drivers/net/dm90x0.c
@@ -1554,8 +1554,9 @@ static int dm9x_addmac(FAR struct net_driver_s *dev, FAR const uint8_t *mac)
 
   /* Add the MAC address to the hardware multicast routing table */
 
-#warning "Multicast MAC support not implemented"
-  return OK;
+  /* #warning "Multicast MAC support not implemented" */
+
+  return -ENOSYS;
 }
 #endif
 
@@ -1585,8 +1586,9 @@ static int dm9x_rmmac(FAR struct net_driver_s *dev, FAR const uint8_t *mac)
 
   /* Add the MAC address to the hardware multicast routing table */
 
-#warning "Multicast MAC support not implemented"
-  return OK;
+  /* #warning "Multicast MAC support not implemented" */
+
+  return -ENOSYS;
 }
 #endif
 
diff --git a/drivers/net/enc28j60.c b/drivers/net/enc28j60.c
index e3809bd1ad7..bfeb5b0e323 100644
--- a/drivers/net/enc28j60.c
+++ b/drivers/net/enc28j60.c
@@ -2084,12 +2084,12 @@ static int enc_addmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 
   /* Add the MAC address to the hardware multicast routing table */
 
-#warning "Multicast MAC support not implemented"
+  /* #warning "Multicast MAC support not implemented" */
 
   /* Un-lock the SPI bus */
 
   enc_unlock(priv);
-  return OK;
+  return -ENOSYS;
 }
 #endif
 
@@ -2122,12 +2122,12 @@ static int enc_rmmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 
   /* Add the MAC address to the hardware multicast routing table */
 
-#warning "Multicast MAC support not implemented"
+  /* #warning "Multicast MAC support not implemented" */
 
   /* Un-lock the SPI bus */
 
   enc_unlock(priv);
-  return OK;
+  return -ENOSYS;
 }
 #endif
 
diff --git a/drivers/net/encx24j600.c b/drivers/net/encx24j600.c
index 2fc85c39d88..fc164f27fb0 100644
--- a/drivers/net/encx24j600.c
+++ b/drivers/net/encx24j600.c
@@ -2228,12 +2228,12 @@ static int enc_addmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 
   /* Add the MAC address to the hardware multicast routing table */
 
-#warning "Multicast MAC support not implemented"
+  /* #warning "Multicast MAC support not implemented" */
 
   /* Un-lock the SPI bus */
 
   enc_unlock(priv);
-  return OK;
+  return -ENOSYS;
 }
 #endif
 
@@ -2266,12 +2266,12 @@ static int enc_rmmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 
   /* Add the MAC address to the hardware multicast routing table */
 
-#warning "Multicast MAC support not implemented"
+  /* #warning "Multicast MAC support not implemented" */
 
   /* Un-lock the SPI bus */
 
   enc_unlock(priv);
-  return OK;
+  return -ENOSYS;
 }
 #endif
 
diff --git a/libs/libc/dlfcn/lib_dlclose.c b/libs/libc/dlfcn/lib_dlclose.c
index 167d92f9152..1721f800360 100644
--- a/libs/libc/dlfcn/lib_dlclose.c
+++ b/libs/libc/dlfcn/lib_dlclose.c
@@ -246,7 +246,8 @@ int dlclose(FAR void *handle)
    * memory region.
    */
 
-#warning Missing logic
+  /* #warning Missing logic */
+
   return -ENOSYS;
 #endif
 }
diff --git a/libs/libc/dlfcn/lib_dlopen.c b/libs/libc/dlfcn/lib_dlopen.c
index 13d7758b24d..fb1a48f3c3f 100644
--- a/libs/libc/dlfcn/lib_dlopen.c
+++ b/libs/libc/dlfcn/lib_dlopen.c
@@ -297,7 +297,8 @@ static inline FAR void *dlinsert(FAR const char *filename)
 
 static inline FAR void *dlinsert(FAR const char *filename)
 {
-#warning Missing logic
+  /* #warning Missing logic */
+
   return NULL;
 }
 #endif
diff --git a/libs/libc/dlfcn/lib_dlsym.c b/libs/libc/dlfcn/lib_dlsym.c
index 75e21b23643..3f82c20bdd7 100644
--- a/libs/libc/dlfcn/lib_dlsym.c
+++ b/libs/libc/dlfcn/lib_dlsym.c
@@ -171,7 +171,8 @@ FAR void *dlsym(FAR void *handle, FAR const char *name)
    * memory region.
    */
 
-#warning Missing logic
+  /* #warning Missing logic */
+
   return NULL;
 #endif
 }
diff --git a/libs/libc/dlfcn/lib_dlsymtab.c b/libs/libc/dlfcn/lib_dlsymtab.c
index 3b3da9a898e..6190bbcb235 100644
--- a/libs/libc/dlfcn/lib_dlsymtab.c
+++ b/libs/libc/dlfcn/lib_dlsymtab.c
@@ -63,7 +63,8 @@ int dlsymtab(FAR const struct symtab_s *symtab, int nsymbols)
    * memory region.
    */
 
-#warning Missing logic
+  /* #warning Missing logic */
+
   return -ENOSYS;
 
 #else
diff --git a/libs/libnx/nxmu/nx_cursor.c b/libs/libnx/nxmu/nx_cursor.c
index ad91bc7c07d..5521f698ea7 100644
--- a/libs/libnx/nxmu/nx_cursor.c
+++ b/libs/libnx/nxmu/nx_cursor.c
@@ -206,7 +206,8 @@ int nxcursor_get_position(NXHANDLE hnd, FAR struct nxgl_point_s *pos)
    * be we don't have the definitions exposed to get it.
    */
 
-#warning Missing logic
+  /* #warning Missing logic */
+
   set_errno(ENOSYS);
   return ERROR;
 }
diff --git a/net/inet/ipv4_setsockopt.c b/net/inet/ipv4_setsockopt.c
index 3207b654068..83bba33a5aa 100644
--- a/net/inet/ipv4_setsockopt.c
+++ b/net/inet/ipv4_setsockopt.c
@@ -224,7 +224,9 @@ int ipv4_setsockopt(FAR struct socket *psock, int option,
       case IP_MULTICAST_ALL:          /* Modify the delivery policy of
                                        * multicast messages bound to
                                        * INADDR_ANY */
-#warning Missing logic
+
+        /* #warning Missing logic */
+
         nwarn("WARNING: Unimplemented IPv4 option: %d\n", option);
         ret = -ENOSYS;
         break;
diff --git a/net/local/local_fifo.c b/net/local/local_fifo.c
index 2c49d237a1e..d5eb3dfc721 100644
--- a/net/local/local_fifo.c
+++ b/net/local/local_fifo.c
@@ -499,7 +499,8 @@ int local_release_halfduplex(FAR struct local_conn_s *conn)
    * would be destroyed.
    */
 
-#  warning Missing logic
+  /* #warning Missing logic */
+
   return OK;
 
 #else
diff --git a/net/local/local_sendmsg.c b/net/local/local_sendmsg.c
index 0fef4d946ab..3a23a086980 100644
--- a/net/local/local_sendmsg.c
+++ b/net/local/local_sendmsg.c
@@ -215,7 +215,7 @@ static ssize_t local_send(FAR struct socket *psock,
         {
           /* Local UDP packet send */
 
-#warning Missing logic
+          /* #warning Missing logic */
 
           ret = -ENOSYS;
         }
diff --git a/net/local/local_sockif.c b/net/local/local_sockif.c
index 8b6a1918f6c..4d44db23ce1 100644
--- a/net/local/local_sockif.c
+++ b/net/local/local_sockif.c
@@ -618,7 +618,7 @@ static int local_connect(FAR struct socket *psock,
         {
           /* Perform the datagram connection logic */
 
-#warning Missing logic
+          /* #warning Missing logic */
 
           return -ENOSYS;
         }
diff --git a/net/utils/net_chksum.c b/net/utils/net_chksum.c
index fb4933a0019..6c350961930 100644
--- a/net/utils/net_chksum.c
+++ b/net/utils/net_chksum.c
@@ -223,10 +223,6 @@ void net_chksum_adjust(FAR uint16_t *chksum,
                        FAR const uint16_t *optr, ssize_t olen,
                        FAR const uint16_t *nptr, ssize_t nlen)
 {
-#ifdef CONFIG_ENDIAN_BIG
-#  warning "Not verified on big-endian yet."
-#endif
-
   int32_t x;
   int32_t oldval;
   int32_t newval;