diff --git a/module/icp/algs/modes/gcm.c b/module/icp/algs/modes/gcm.c
index 3fee18cd7ef0..73286300a32d 100644
--- a/module/icp/algs/modes/gcm.c
+++ b/module/icp/algs/modes/gcm.c
@@ -1075,8 +1075,13 @@ extern void ASMABI gcm_ghash_vpclmulqdq_avx2(uint64_t ghash[2],
 static inline void GHASH_AVX(gcm_ctx_t *ctx, const uint8_t *in, size_t len)
 {
 	if (ctx->gcm_use_avx2) {
+		uint64_t compare[2];
+		memcpy(compare, ctx->gcm_ghash, sizeof(compare));
+		gcm_ghash_avx(compare,
+		    (const uint64_t *)ctx->gcm_Htable, in, len);
 		gcm_ghash_vpclmulqdq_avx2(ctx->gcm_ghash,
 		    (const uint64_t *)ctx->gcm_Htable, in, len);
+		    ASSERT0F(memcmp(compare, ctx->gcm_ghash, sizeof(compare)), "%s", "ghash mismatch");
 	} else {
 		gcm_ghash_avx(ctx->gcm_ghash,
 		    (const uint64_t *)ctx->gcm_Htable, in, len);
@@ -1233,7 +1238,7 @@ gcm_mode_encrypt_contiguous_blocks_avx(gcm_ctx_t *ctx, char *data,
 	size_t done = 0;
 	uint8_t *datap = (uint8_t *)data;
 	size_t chunk_size = (size_t)GCM_CHUNK_SIZE_READ;
-	aesni_gcm_encrypt_impl *encrypt_blocks = ctx->gcm_use_avx2 ?
+	aesni_gcm_encrypt_impl *encrypt_blocks = B_FALSE ?
 	    aesni_gcm_encrypt_avx2 : aesni_gcm_encrypt_avx;
 	const aes_key_t *key = ((aes_key_t *)ctx->gcm_keysched);
 	uint64_t *ghash = ctx->gcm_ghash;
@@ -1473,7 +1478,7 @@ gcm_decrypt_final_avx(gcm_ctx_t *ctx, crypto_data_t *out, size_t block_size)
 	    B_FALSE);
 
 	size_t chunk_size = (size_t)GCM_CHUNK_SIZE_READ;
-	aesni_gcm_decrypt_impl *decrypt_blocks = ctx->gcm_use_avx2 ?
+	aesni_gcm_decrypt_impl *decrypt_blocks = B_FALSE ?
 	    aesni_gcm_decrypt_avx2 : aesni_gcm_decrypt_avx;
 	size_t pt_len = ctx->gcm_processed_data_len - ctx->gcm_tag_len;
 	uint8_t *datap = ctx->gcm_pt_buf;
@@ -1574,6 +1579,50 @@ gcm_decrypt_final_avx(gcm_ctx_t *ctx, crypto_data_t *out, size_t block_size)
 	return (CRYPTO_SUCCESS);
 }
 
+static void
+dump_bin(char *out, size_t out_len, const void* in, size_t in_len)
+{
+	const char* in_c = in;
+	const char *end = in_c + in_len;
+	for ( ; in_c != end; in_c++) {
+		int count = snprintf(out, out_len, "%02x ", (unsigned)*in_c);
+		if (out_len < count) {
+			break;
+		}
+
+		out_len -= count;
+		out += count;
+	}
+}
+
+static void
+assert_buf_eq(const void *l, const void *r, size_t len, const char* msg)
+{
+	if (!memcmp(l, r, len)) {
+		return;
+	}
+
+	size_t compare_str_size = len * 3 + 1;
+	char *compare_hex = vmem_alloc(compare_str_size, KM_SLEEP);
+	if (!compare_hex) {
+		ASSERT0F(memcmp(l, r, len), "%s", msg);
+		return;
+	}
+	char *actual_hex = vmem_alloc(compare_str_size, KM_SLEEP);
+	if (!actual_hex) {
+		ASSERT0F(memcmp(l, r, len), "%s", msg);
+		goto free_compare;
+	}
+
+	dump_bin(compare_hex, compare_str_size, l, len);
+	dump_bin(actual_hex, compare_str_size, r, len);
+	ASSERT0F(memcmp(l, r, len), "%s\nexpected: %s\nactual: %s", msg, compare_hex, actual_hex);
+
+	vmem_free(actual_hex, compare_str_size);
+free_compare:
+	vmem_free(compare_hex, compare_str_size);
+}
+
 /*
  * Initialize the GCM params H, Htabtle and the counter block. Save the
  * initial counter block.
@@ -1602,7 +1651,10 @@ gcm_init_avx(gcm_ctx_t *ctx, const uint8_t *iv, size_t iv_len,
 	    (const uint32_t *)H, (uint32_t *)H);
 
 	if (ctx->gcm_use_avx2) {
+		uint64_t compare[(2 * 6 * 2)];
 		gcm_init_vpclmulqdq_avx2((uint128_t *)ctx->gcm_Htable, H);
+		gcm_init_htab_avx(compare, H);
+		assert_buf_eq(compare, ctx->gcm_Htable, ctx->gcm_htab_len, "htab differs");
 	} else {
 		gcm_init_htab_avx(ctx->gcm_Htable, H);
 	}