diff --git a/print-esp.c b/print-esp.c
index 748fb4a1..6ba92eda 100644
--- a/print-esp.c
+++ b/print-esp.c
@@ -191,23 +191,23 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
 		return 0;
 	if (EVP_CipherInit(ctx, sa->evp, sa->secret, NULL, 0) < 0)
 		(*ndo->ndo_warning)(ndo, "espkey init failed");
-        EVP_CipherInit(ctx, NULL, NULL, iv, 0);
+	EVP_CipherInit(ctx, NULL, NULL, iv, 0);
 
-        /* We need a block size */
-        block_size = EVP_CIPHER_CTX_block_size(ctx);
-        /* We need the buffer size to be multiple of a block size */
-        output_buffer_size = len + (block_size - len % block_size);
-        output_buffer = (u_char *)calloc(output_buffer_size, sizeof(u_char));
+	/* We need a block size */
+	block_size = EVP_CIPHER_CTX_block_size(ctx);
+	/* We need the buffer size to be multiple of a block size */
+	output_buffer_size = len + (block_size - len % block_size);
+	output_buffer = (u_char *)calloc(output_buffer_size, sizeof(u_char));
 	/* EVP_Cipher output buffer should be different from the input one.
-         * Also it should be of size that is multiple of cipher block size. */
+	 * Also it should be of size that is multiple of cipher block size. */
 	EVP_Cipher(ctx, output_buffer, buf, len);
 	EVP_CIPHER_CTX_free(ctx);
 
-        buf_mut = (u_char*) buf;
-        /* Of course this is wrong, because buf is a const buffer, but changing this
-         * would require more complicated fix. */
-        memcpy(buf_mut, output_buffer, len);
-        free(output_buffer);
+	buf_mut = (u_char*) buf;
+	/* Of course this is wrong, because buf is a const buffer, but changing this
+	 * would require more complicated fix. */
+	memcpy(buf_mut, output_buffer, len);
+	free(output_buffer);
 
 	ndo->ndo_packetp = buf;
 	ndo->ndo_snapend = end;