diff --git a/hs20/client/est.c b/hs20/client/est.c
index 97f9132..c3f27e1 100644
--- a/hs20/client/est.c
+++ b/hs20/client/est.c
@@ -17,9 +17,7 @@
 #include <openssl/x509.h>
 #include <openssl/x509v3.h>
 #include <openssl/opensslv.h>
-#ifdef OPENSSL_IS_BORINGSSL
-#include <openssl/buf.h>
-#endif /* OPENSSL_IS_BORINGSSL */
+#include <openssl/buffer.h>
 
 #include "common.h"
 #include "utils/base64.h"
@@ -220,9 +218,7 @@
 	} d;
 } AttrOrOID;
 
-#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(OPENSSL_IS_BORINGSSL)
 DEFINE_STACK_OF(AttrOrOID)
-#endif
 
 typedef struct {
 	int type;
@@ -340,30 +336,13 @@
 	if (!csrattrs || ! csrattrs->attrs)
 		return;
 
-#ifdef OPENSSL_IS_BORINGSSL
-	num = sk_num(CHECKED_CAST(_STACK *, STACK_OF(AttrOrOID) *,
-				  csrattrs->attrs));
-	for (i = 0; i < num; i++) {
-		AttrOrOID *ao = sk_value(
-			CHECKED_CAST(_STACK *, const STACK_OF(AttrOrOID) *,
-				     csrattrs->attrs), i);
-		switch (ao->type) {
-		case 0:
-			add_csrattrs_oid(ctx, ao->d.oid, exts);
-			break;
-		case 1:
-			add_csrattrs_attr(ctx, ao->d.attribute, exts);
-			break;
-		}
-	}
-#else /* OPENSSL_IS_BORINGSSL */
-#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(OPENSSL_IS_BORINGSSL)
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L
 	num = sk_AttrOrOID_num(csrattrs->attrs);
 #else
 	num = SKM_sk_num(AttrOrOID, csrattrs->attrs);
 #endif
 	for (i = 0; i < num; i++) {
-#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(OPENSSL_IS_BORINGSSL)
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L
 		AttrOrOID *ao = sk_AttrOrOID_value(csrattrs->attrs, i);
 #else
 		AttrOrOID *ao = SKM_sk_value(AttrOrOID, csrattrs->attrs, i);
@@ -377,7 +356,6 @@
 			break;
 		}
 	}
-#endif /* OPENSSL_IS_BORINGSSL */
 }