diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index a4bb35f..55be595 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -60,8 +60,9 @@
 #endif
 
 #if defined(MBEDTLS_RSA_C)
-static int rsa_can_do( mbedtls_pk_type_t type )
+static int rsa_can_do( const void *ctx, mbedtls_pk_type_t type )
 {
+    (void) ctx;
     return( type == MBEDTLS_PK_RSA ||
             type == MBEDTLS_PK_RSASSA_PSS );
 }
@@ -201,8 +202,9 @@
 /*
  * Generic EC key
  */
-static int eckey_can_do( mbedtls_pk_type_t type )
+static int eckey_can_do( const void *ctx, mbedtls_pk_type_t type )
 {
+    (void) ctx;
     return( type == MBEDTLS_PK_ECKEY ||
             type == MBEDTLS_PK_ECKEY_DH ||
             type == MBEDTLS_PK_ECDSA );
@@ -314,8 +316,9 @@
 /*
  * EC key restricted to ECDH
  */
-static int eckeydh_can_do( mbedtls_pk_type_t type )
+static int eckeydh_can_do( const void *ctx, mbedtls_pk_type_t type )
 {
+    (void) ctx;
     return( type == MBEDTLS_PK_ECKEY ||
             type == MBEDTLS_PK_ECKEY_DH );
 }
@@ -337,8 +340,9 @@
 #endif /* MBEDTLS_ECP_C */
 
 #if defined(MBEDTLS_ECDSA_C)
-static int ecdsa_can_do( mbedtls_pk_type_t type )
+static int ecdsa_can_do( const void *ctx, mbedtls_pk_type_t type )
 {
+    (void) ctx;
     return( type == MBEDTLS_PK_ECDSA );
 }
 
@@ -404,8 +408,9 @@
  * Support for alternative RSA-private implementations
  */
 
-static int rsa_alt_can_do( mbedtls_pk_type_t type )
+static int rsa_alt_can_do( const void *ctx, mbedtls_pk_type_t type )
 {
+    (void) ctx;
     return( type == MBEDTLS_PK_RSA );
 }