diff --git a/include/polarssl/error.h b/include/polarssl/error.h
index 10e68f8..889e4be 100644
--- a/include/polarssl/error.h
+++ b/include/polarssl/error.h
@@ -77,7 +77,7 @@
  * PEM      1   9
  * PKCS#12  1   4 (Started from top)
  * X509     2   25
- * PK       2   1 (Started from top)
+ * PK       2   3 (Started from top)
  * DHM      3   6
  * PKCS5    3   4 (Started from top)
  * RSA      4   9
diff --git a/include/polarssl/pk.h b/include/polarssl/pk.h
index 6a3d4b8..a39fadf 100644
--- a/include/polarssl/pk.h
+++ b/include/polarssl/pk.h
@@ -43,7 +43,8 @@
 #endif
 
 #define POLARSSL_ERR_PK_MALLOC_FAILED       -0x2F80  /**< Memory alloation failed. */
-#define POLARSSL_ERR_PK_TYPE_MISMATCH       -0x2F00  /**< Type mismatch, eg attempt to use a RSA key as EC, or to modify key type */
+#define POLARSSL_ERR_PK_TYPE_MISMATCH       -0x2F00  /**< Type mismatch, eg attempt to use a RSA key as EC, or to modify key type. */
+#define POLARSSL_ERR_PK_BAD_INPUT_DATA      -0x2E80  /**< Bad input parameters to function. */
 
 #if defined(POLARSSL_RSA_C)
 /**
diff --git a/library/error.c b/library/error.c
index 333a8f8..0ea3c29 100644
--- a/library/error.c
+++ b/library/error.c
@@ -252,6 +252,8 @@
             snprintf( buf, buflen, "PK - Memory alloation failed" );
         if( use_ret == -(POLARSSL_ERR_PK_TYPE_MISMATCH) )
             snprintf( buf, buflen, "PK - Type mismatch, eg attempt to use a RSA key as EC, or to modify key type" );
+        if( use_ret == -(POLARSSL_ERR_PK_BAD_INPUT_DATA) )
+            snprintf( buf, buflen, "PK - Bad input parameters to function" );
 #endif /* POLARSSL_PK_C */
 
 #if defined(POLARSSL_PKCS12_C)
diff --git a/library/pk.c b/library/pk.c
index d8b4c85..61544eb 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -38,15 +38,6 @@
 #include "polarssl/ecdsa.h"
 #endif
 
-#if defined(POLARSSL_MEMORY_C)
-#include "polarssl/memory.h"
-#else
-#define polarssl_malloc     malloc
-#define polarssl_free       free
-#endif
-
-#include <stdlib.h>
-
 /*
  * Initialise a pk_context
  */
@@ -114,7 +105,7 @@
     }
 
     if( ( info = pk_info_from_type( type ) ) == NULL )
-        return( POLARSSL_ERR_PK_TYPE_MISMATCH );
+        return( POLARSSL_ERR_PK_BAD_INPUT_DATA );
 
     if( ( ctx->pk_ctx = info->ctx_alloc_func() ) == NULL )
         return( POLARSSL_ERR_PK_MALLOC_FAILED );
@@ -144,7 +135,7 @@
                const unsigned char *sig, size_t sig_len )
 {
     if( ctx == NULL || ctx->pk_info == NULL )
-        return( POLARSSL_ERR_PK_TYPE_MISMATCH ); // TODO
+        return( POLARSSL_ERR_PK_BAD_INPUT_DATA );
 
     return( ctx->pk_info->verify_func( ctx->pk_ctx, hash, md_info, sig, sig_len ) );
 }
@@ -166,7 +157,7 @@
 int pk_debug( const pk_context *ctx, pk_debug_item *items )
 {
     if( ctx == NULL || ctx->pk_info == NULL )
-        return( POLARSSL_ERR_PK_TYPE_MISMATCH ); // TODO
+        return( POLARSSL_ERR_PK_BAD_INPUT_DATA );
 
     ctx->pk_info->debug_func( ctx->pk_ctx, items );
     return( 0 );