diff --git a/src/core/ipv4/ip4.c b/src/core/ipv4/ip4.c
index 9fa9b566..ff7b937c 100644
--- a/src/core/ipv4/ip4.c
+++ b/src/core/ipv4/ip4.c
@@ -106,7 +106,9 @@ static u16_t ip_id;
 /** The default netif used for multicast */
 static struct netif* ip4_default_multicast_netif;
 
-/** Set a default netif for IPv4 multicast. */
+/**
+ * @ingroup ip4
+ * Set a default netif for IPv4 multicast. */
 void
 ip4_set_default_multicast_netif(struct netif* default_multicast_netif)
 {
@@ -713,7 +715,6 @@ ip4_input(struct pbuf *p, struct netif *inp)
 }
 
 /**
- * @ingroup ip4
  * Sends an IP packet on a network interface. This function constructs
  * the IP header and calculates the IP header checksum. If the source
  * IP address is NULL, the IP address of the outgoing network
@@ -748,7 +749,6 @@ ip4_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
 }
 
 /**
- * @ingroup ip4
  * Same as ip_output_if() but with the possibility to include IP options:
  *
  * @ param ip_options pointer to the IP options, copied into the IP header
@@ -776,7 +776,6 @@ ip4_output_if_opt(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
 }
 
 /**
- * @ingroup ip4
  * Same as ip_output_if() but 'src' address is not replaced by netif address
  * when it is 'any'.
  */
@@ -790,7 +789,6 @@ ip4_output_if_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
 }
 
 /**
- * @ingroup ip4
  * Same as ip_output_if_opt() but 'src' address is not replaced by netif address
  * when it is 'any'.
  */
@@ -952,7 +950,6 @@ ip4_output_if_opt_src(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *d
 }
 
 /**
- * @ingroup ip4
  * Simple interface to ip_output_if. It finds the outgoing network
  * interface and calls upon ip_output_if to do the actual work.
  *
diff --git a/src/core/ipv6/ip6.c b/src/core/ipv6/ip6.c
index 6a953f06..bfbe453f 100644
--- a/src/core/ipv6/ip6.c
+++ b/src/core/ipv6/ip6.c
@@ -778,7 +778,6 @@ ip6_input_cleanup:
 
 
 /**
- * @ingroup ip6
  * Sends an IPv6 packet on a network interface. This function constructs
  * the IPv6 header. If the source IPv6 address is NULL, the IPv6 "ANY" address is
  * used as source (usually during network startup). If the source IPv6 address it
@@ -823,7 +822,6 @@ ip6_output_if(struct pbuf *p, const ip6_addr_t *src, const ip6_addr_t *dest,
 }
 
 /**
- * @ingroup ip6
  * Same as ip6_output_if() but 'src' address is not replaced by netif address
  * when it is 'any'.
  */
@@ -907,7 +905,6 @@ ip6_output_if_src(struct pbuf *p, const ip6_addr_t *src, const ip6_addr_t *dest,
 }
 
 /**
- * @ingroup ip6
  * Simple interface to ip6_output_if. It finds the outgoing network
  * interface and calls upon ip6_output_if to do the actual work.
  *
diff --git a/src/include/lwip/pbuf.h b/src/include/lwip/pbuf.h
index 509bd475..60eee456 100644
--- a/src/include/lwip/pbuf.h
+++ b/src/include/lwip/pbuf.h
@@ -80,8 +80,7 @@ typedef enum {
    */
   PBUF_IP,
   /** Includes spare room for link layer header (ethernet header).
-   * Use this if you intend to pass the pbuf to functions like ip4_output(),
-   * ip6_output() or ip_output().
+   * Use this if you intend to pass the pbuf to functions like ip_output().
    * @see @ref PBUF_LINK_HLEN
    */
   PBUF_LINK,