diff --git a/include/mbedtls/pk_internal.h b/include/mbedtls/pk_internal.h
index fd89aa9..65bd8e9 100644
--- a/include/mbedtls/pk_internal.h
+++ b/include/mbedtls/pk_internal.h
@@ -41,6 +41,9 @@
  * Each PK type that can be used with MBEDTLS_PK_SINGLE_TYPE needs to have
  * the following MBEDTLS_PK_INFO_{FIELD} definitions, plus a dummy one for the
  * base name. For now, only ECKEY with MBEDTLS_USE_TINYCRYPT is defined.
+ *
+ * For optional functions that are omitted, we need both the _FUNC field
+ * defined to NULL, and an extra macro _OMIT defined to 1.
  */
 
 #if defined(MBEDTLS_USE_TINYCRYPT)
@@ -54,11 +57,14 @@
 #define MBEDTLS_PK_INFO_ECKEY_VERIFY_FUNC       uecc_eckey_verify_wrap
 #define MBEDTLS_PK_INFO_ECKEY_SIGN_FUNC         uecc_eckey_sign_wrap
 #define MBEDTLS_PK_INFO_ECKEY_DECRYPT_FUNC      NULL
+#define MBEDTLS_PK_INFO_ECKEY_DECRYPT_OMIT      1
 #define MBEDTLS_PK_INFO_ECKEY_ENCRYPT_FUNC      NULL
+#define MBEDTLS_PK_INFO_ECKEY_ENCRYPT_OMIT      1
 #define MBEDTLS_PK_INFO_ECKEY_CHECK_PAIR_FUNC   uecc_eckey_check_pair
 #define MBEDTLS_PK_INFO_ECKEY_CTX_ALLOC_FUNC    uecc_eckey_alloc_wrap
 #define MBEDTLS_PK_INFO_ECKEY_CTX_FREE_FUNC     uecc_eckey_free_wrap
 #define MBEDTLS_PK_INFO_ECKEY_DEBUG_FUNC        NULL
+#define MBEDTLS_PK_INFO_ECKEY_DEBUG_OMIT        1
 #endif /* MBEDTLS_USE_TINYCRYPT */
 
 /*
@@ -69,13 +75,19 @@
 #define MBEDTLS_PK_INFO_GET_BITLEN_T( PK )      PK ## _GET_BITLEN
 #define MBEDTLS_PK_INFO_CAN_DO_T( PK )          PK ## _CAN_DO
 #define MBEDTLS_PK_INFO_VERIFY_FUNC_T( PK )     PK ## _VERIFY_FUNC
+#define MBEDTLS_PK_INFO_VERIFY_OMIT_T( PK )     PK ## _VERIFY_OMIT
 #define MBEDTLS_PK_INFO_SIGN_FUNC_T( PK )       PK ## _SIGN_FUNC
+#define MBEDTLS_PK_INFO_SIGN_OMIT_T( PK )       PK ## _SIGN_OMIT
 #define MBEDTLS_PK_INFO_DECRYPT_FUNC_T( PK )    PK ## _DECRYPT_FUNC
+#define MBEDTLS_PK_INFO_DECRYPT_OMIT_T( PK )    PK ## _DECRYPT_OMIT
 #define MBEDTLS_PK_INFO_ENCRYPT_FUNC_T( PK )    PK ## _ENCRYPT_FUNC
+#define MBEDTLS_PK_INFO_ENCRYPT_OMIT_T( PK )    PK ## _ENCRYPT_OMIT
 #define MBEDTLS_PK_INFO_CHECK_PAIR_FUNC_T( PK ) PK ## _CHECK_PAIR_FUNC
+#define MBEDTLS_PK_INFO_CHECK_PAIR_OMIT_T( PK ) PK ## _CHECK_PAIR_OMIT
 #define MBEDTLS_PK_INFO_CTX_ALLOC_FUNC_T( PK )  PK ## _CTX_ALLOC_FUNC
 #define MBEDTLS_PK_INFO_CTX_FREE_FUNC_T( PK )   PK ## _CTX_FREE_FUNC
 #define MBEDTLS_PK_INFO_DEBUG_FUNC_T( PK )      PK ## _DEBUG_FUNC
+#define MBEDTLS_PK_INFO_DEBUG_OMIT_T( PK )      PK ## _DEBUG_OMIT
 
 /* Wrappers around MBEDTLS_PK_INFO_{FIELD}_T() which makes sure that
  * the argument is macro-expanded before concatenated with the
@@ -87,13 +99,19 @@
 #define MBEDTLS_PK_INFO_GET_BITLEN( PK )      MBEDTLS_PK_INFO_GET_BITLEN_T( PK )
 #define MBEDTLS_PK_INFO_CAN_DO( PK )          MBEDTLS_PK_INFO_CAN_DO_T( PK )
 #define MBEDTLS_PK_INFO_VERIFY_FUNC( PK )     MBEDTLS_PK_INFO_VERIFY_FUNC_T( PK )
+#define MBEDTLS_PK_INFO_VERIFY_OMIT( PK )     MBEDTLS_PK_INFO_VERIFY_OMIT_T( PK )
 #define MBEDTLS_PK_INFO_SIGN_FUNC( PK )       MBEDTLS_PK_INFO_SIGN_FUNC_T( PK )
+#define MBEDTLS_PK_INFO_SIGN_OMIT( PK )       MBEDTLS_PK_INFO_SIGN_OMIT_T( PK )
 #define MBEDTLS_PK_INFO_DECRYPT_FUNC( PK )    MBEDTLS_PK_INFO_DECRYPT_FUNC_T( PK )
+#define MBEDTLS_PK_INFO_DECRYPT_OMIT( PK )    MBEDTLS_PK_INFO_DECRYPT_OMIT_T( PK )
 #define MBEDTLS_PK_INFO_ENCRYPT_FUNC( PK )    MBEDTLS_PK_INFO_ENCRYPT_FUNC_T( PK )
+#define MBEDTLS_PK_INFO_ENCRYPT_OMIT( PK )    MBEDTLS_PK_INFO_ENCRYPT_OMIT_T( PK )
 #define MBEDTLS_PK_INFO_CHECK_PAIR_FUNC( PK ) MBEDTLS_PK_INFO_CHECK_PAIR_FUNC_T( PK )
+#define MBEDTLS_PK_INFO_CHECK_PAIR_OMIT( PK ) MBEDTLS_PK_INFO_CHECK_PAIR_OMIT_T( PK )
 #define MBEDTLS_PK_INFO_CTX_ALLOC_FUNC( PK )  MBEDTLS_PK_INFO_CTX_ALLOC_FUNC_T( PK )
 #define MBEDTLS_PK_INFO_CTX_FREE_FUNC( PK )   MBEDTLS_PK_INFO_CTX_FREE_FUNC_T( PK )
 #define MBEDTLS_PK_INFO_DEBUG_FUNC( PK )      MBEDTLS_PK_INFO_DEBUG_FUNC_T( PK )
+#define MBEDTLS_PK_INFO_DEBUG_OMIT( PK )      MBEDTLS_PK_INFO_DEBUG_OMIT_T( PK )
 
 struct mbedtls_pk_info_t
 {