diff --git a/wolfssl/wolfcrypt/cryptocb.h b/wolfssl/wolfcrypt/cryptocb.h
index 7b1753381..f5a081f9a 100644
--- a/wolfssl/wolfcrypt/cryptocb.h
+++ b/wolfssl/wolfcrypt/cryptocb.h
@@ -75,10 +75,15 @@
 /* Crypto Information Structure for callbacks */
 typedef struct wc_CryptoInfo {
     int algo_type; /* enum wc_AlgoType */
+#if HAVE_ANONYMOUS_INLINE_AGGREGATES
+    union {
+#endif
 #if !defined(NO_RSA) || defined(HAVE_ECC)
     struct {
         int type; /* enum wc_PkType */
+#if HAVE_ANONYMOUS_INLINE_AGGREGATES
         union {
+#endif
         #ifndef NO_RSA
             struct {
                 const byte* in;
@@ -182,14 +187,18 @@ typedef struct wc_CryptoInfo {
                 byte         contextLen;
             } ed25519verify;
         #endif
+#if HAVE_ANONYMOUS_INLINE_AGGREGATES
         };
+#endif
     } pk;
 #endif /* !NO_RSA || HAVE_ECC */
 #if !defined(NO_AES) || !defined(NO_DES3)
     struct {
         int type; /* enum wc_CipherType */
         int enc;
+#if HAVE_ANONYMOUS_INLINE_AGGREGATES
         union {
+#endif
         #ifdef HAVE_AESGCM
             struct {
                 Aes*        aes;
@@ -232,7 +241,9 @@ typedef struct wc_CryptoInfo {
                 word32      sz;
             } des3;
         #endif
+#if HAVE_ANONYMOUS_INLINE_AGGREGATES
         };
+#endif
     } cipher;
 #endif /* !NO_AES || !NO_DES3 */
 #if !defined(NO_SHA) || !defined(NO_SHA256) || \
@@ -242,7 +253,9 @@ typedef struct wc_CryptoInfo {
         const byte* in;
         word32 inSz;
         byte* digest;
+#if HAVE_ANONYMOUS_INLINE_AGGREGATES
         union {
+#endif
         #ifndef NO_SHA
             wc_Sha* sha1;
         #endif
@@ -255,7 +268,9 @@ typedef struct wc_CryptoInfo {
         #ifdef WOLFSSL_SHA512
             wc_Sha512* sha512;
         #endif
+#if HAVE_ANONYMOUS_INLINE_AGGREGATES
         };
+#endif
     } hash;
 #endif /* !NO_SHA || !NO_SHA256 */
 #ifndef NO_HMAC
@@ -292,6 +307,9 @@ typedef struct wc_CryptoInfo {
         int type;
     } cmac;
 #endif
+#if HAVE_ANONYMOUS_INLINE_AGGREGATES
+    };
+#endif
 } wc_CryptoInfo;
 
 
diff --git a/wolfssl/wolfcrypt/types.h b/wolfssl/wolfcrypt/types.h
index 7bc885194..8981619fa 100644
--- a/wolfssl/wolfcrypt/types.h
+++ b/wolfssl/wolfcrypt/types.h
@@ -95,6 +95,17 @@ decouple library dependencies with standard string, memory and so on.
         typedef const char* const wcchar;
     #endif
 
+    #ifndef HAVE_ANONYMOUS_INLINE_AGGREGATES
+        /* if __STDC__, pivot on the version, otherwise guess it's allowed,
+         * subject to override.
+         */
+        #if !defined(__STDC__) \
+            || (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201101L))
+            #define HAVE_ANONYMOUS_INLINE_AGGREGATES 1
+        #else
+            #define HAVE_ANONYMOUS_INLINE_AGGREGATES 0
+        #endif
+    #endif
 
     /* try to set SIZEOF_LONG or SIZEOF_LONG_LONG if user didn't */
     #if defined(_MSC_VER) || defined(HAVE_LIMITS_H)
diff --git a/wolfssl/wolfcrypt/wc_port.h b/wolfssl/wolfcrypt/wc_port.h
index ca71bf7d9..b94429281 100644
--- a/wolfssl/wolfcrypt/wc_port.h
+++ b/wolfssl/wolfcrypt/wc_port.h
@@ -130,6 +130,11 @@
 
     _Pragma("GCC diagnostic pop");
 
+    /* the kernel uses -std=c89, but not -pedantic, and makes full use of anon
+     * structs/unions, so we should too.
+     */
+    #define HAVE_ANONYMOUS_INLINE_AGGREGATES 1
+
     /* Linux headers define these using C expressions, but we need
      * them to be evaluable by the preprocessor, for use in sp_int.h.
      */