diff --git a/include/polarssl/error.h b/include/polarssl/error.h
index 0c3fb80..7658814 100644
--- a/include/polarssl/error.h
+++ b/include/polarssl/error.h
@@ -103,7 +103,11 @@
  * \param buffer    buffer to place representation in
  * \param buflen    length of the buffer
  */
+void polarssl_strerror( int errnum, char *buffer, size_t buflen );
+
+#if defined(POLARSSL_ERROR_STRERROR_BC)
 void error_strerror( int errnum, char *buffer, size_t buflen );
+#endif
 
 #ifdef __cplusplus
 }