diff --git a/src/include/lwip/icmp.h b/src/include/lwip/icmp.h
index 4366901e..0ca6522a 100644
--- a/src/include/lwip/icmp.h
+++ b/src/include/lwip/icmp.h
@@ -75,7 +75,7 @@ enum icmp_te_type {
 #  include "arch/bpstruct.h"
 #endif
 /** This is the standard ICMP header only that the u32_t data
- *  is splitted to two u16_t like ICMP echo needs it.
+ *  is split to two u16_t like ICMP echo needs it.
  *  This header is also used for other ICMP types that do not
  *  use the data part.
  */
diff --git a/src/include/lwip/ip4.h b/src/include/lwip/ip4.h
index 5fc7f81f..c49a771e 100644
--- a/src/include/lwip/ip4.h
+++ b/src/include/lwip/ip4.h
@@ -73,7 +73,7 @@ struct ip_hdr {
   /* fragment offset field */
   PACK_STRUCT_FIELD(u16_t _offset);
 #define IP_RF 0x8000U        /* reserved fragment flag */
-#define IP_DF 0x4000U        /* dont fragment flag */
+#define IP_DF 0x4000U        /* don't fragment flag */
 #define IP_MF 0x2000U        /* more fragments flag */
 #define IP_OFFMASK 0x1fffU   /* mask for fragmenting bits */
   /* time to live */