diff --git a/library/base64.c b/library/base64.c
index 21cd3a6..684c537 100644
--- a/library/base64.c
+++ b/library/base64.c
@@ -37,11 +37,15 @@
 #include <inttypes.h>
 #endif
 
+#if defined(POLARSSL_SELF_TEST)
+#include <string.h>
 #if defined(POLARSSL_PLATFORM_C)
 #include "polarssl/platform.h"
 #else
+#include <stdio.h>
 #define polarssl_printf printf
-#endif
+#endif /* POLARSSL_PLATFORM_C */
+#endif /* POLARSSL_SELF_TEST */
 
 static const unsigned char base64_enc_map[64] =
 {
@@ -221,9 +225,6 @@
 
 #if defined(POLARSSL_SELF_TEST)
 
-#include <string.h>
-#include <stdio.h>
-
 static const unsigned char base64_test_dec[64] =
 {
     0x24, 0x48, 0x6E, 0x56, 0x87, 0x62, 0x5A, 0xBD,