diff --git a/src/openvpn/siphash.h b/src/openvpn/siphash.h
index bddddc3..ade7762 100644
--- a/src/openvpn/siphash.h
+++ b/src/openvpn/siphash.h
@@ -18,26 +18,63 @@
 #ifndef SIPHASH_H
 #define SIPHASH_H
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #include <stdint.h>
 #include <stdio.h>
 #include <stdbool.h>
 
+/* We need to include this to check for the OPENSSL_IS_AWSLC macro */
+#ifdef ENABLE_CRYPTO_OPENSSL
+#include <openssl/opensslv.h>
+#endif
+
 /* siphash always uses 128-bit keys */
 #define SIPHASH_KEY_SIZE 16
 
 /**
  * Calculates SIPHASH using the reference implementation
  */
-int
+void
 siphash_reference(const void *in, size_t inlen, const void *k,
                   uint8_t *out, size_t outlen);
 
 
-static inline int
+#if defined(OPENSSL_IS_AWSLC)
+#define USE_CRYPOTOLIB_SIPHASH
+#include <openssl/siphash.h>
+#include <string.h>
+#include "error.h"
+/**
+ *  Computes a SipHash value
+ * @param   in      pointer to input data (read-only)
+ * @param   inlen   input data length in bytes (any size_t value)
+ * @param   k       pointer to the key data (read-only), must be 16 bytes
+ * @param   out     pointer to output data (write-only), outlen bytes must be allocated
+ * @param   outlen  length of the output in bytes, must be 8
+ */
+static inline void
+siphash_cryptolib(const void *in, const size_t inlen,
+                  const void *k, uint8_t *out, const size_t outlen)
+{
+    ASSERT(outlen == sizeof(uint64_t));
+    uint64_t sipout = SIPHASH_24(k, in, inlen);
+
+    memcpy(out, &sipout, sizeof(uint64_t));
+}
+#endif
+
+static inline void
 siphash(const void *in, size_t inlen, const void *k,
         uint8_t *out, size_t outlen)
 {
-    return siphash_reference(in, inlen, k, out, outlen);
+#if defined(USE_CRYPOTOLIB_SIPHASH)
+    siphash_cryptolib(in, inlen, k, out, outlen);
+#else
+    siphash_reference(in, inlen, k, out, outlen);
+#endif
 }
 
-#endif /* ifndef SIPHASH_H */
\ No newline at end of file
+#endif /* ifndef SIPHASH_H */
diff --git a/src/openvpn/siphash_reference.c b/src/openvpn/siphash_reference.c
index ad19a51..5f0adb9 100644
--- a/src/openvpn/siphash_reference.c
+++ b/src/openvpn/siphash_reference.c
@@ -99,7 +99,7 @@
  * out: pointer to output data (write-only), outlen bytes must be allocated
  *  outlen: length of the output in bytes, must be 8 or 16
  */
-int
+void
 siphash_reference(const void *in, const size_t inlen, const void *k, uint8_t *out,
                   const size_t outlen)
 {
@@ -206,7 +206,7 @@
 
     if (outlen == 8)
     {
-        return 0;
+        return;
     }
 
     v1 ^= 0xdd;
@@ -219,6 +219,4 @@
 
     b = v0 ^ v1 ^ v2 ^ v3;
     U64TO8_LE(out + 8, b);
-
-    return 0;
 }