diff --git a/include/openssl/poly1305.h b/include/openssl/poly1305.h
index d42d6ce..b4e23e2 100644
--- a/include/openssl/poly1305.h
+++ b/include/openssl/poly1305.h
@@ -22,10 +22,7 @@
 #endif
 
 
-typedef union {
-  double align;
-  uint8_t bytes[512];
-} poly1305_state;
+typedef uint8_t poly1305_state[512];
 
 /* CRYPTO_poly1305_init sets up |state| so that it can be used to calculate an
  * authentication tag with the one-time key |key|. Note that |key| is a