diff --git a/library/entropy.c b/library/entropy.c
index 7604e0f..846d5ee 100644
--- a/library/entropy.c
+++ b/library/entropy.c
@@ -31,10 +31,21 @@
 #include "polarssl/entropy.h"
 #include "polarssl/entropy_poll.h"
 
+#include <string.h>
+
 #if defined(POLARSSL_FS_IO)
 #include <stdio.h>
 #endif
 
+#if defined(POLARSSL_SELF_TEST)
+#if defined(POLARSSL_PLATFORM_C)
+#include "polarssl/platform.h"
+#else
+#include <stdio.h>
+#define polarssl_printf     printf
+#endif /* POLARSSL_PLATFORM_C */
+#endif /* POLARSSL_SELF_TEST */
+
 #if defined(POLARSSL_HAVEGE_C)
 #include "polarssl/havege.h"
 #endif
@@ -378,14 +389,6 @@
 #endif /* POLARSSL_FS_IO */
 
 #if defined(POLARSSL_SELF_TEST)
-
-#if defined(POLARSSL_PLATFORM_C)
-#include "polarssl/platform.h"
-#else
-#include <stdio.h>
-#define polarssl_printf     printf
-#endif
-
 /*
  * Dummy source function
  */