diff --git a/lib/libcrypto/ui/ui_lib.c b/lib/libcrypto/ui/ui_lib.c
index e7587beea1d..3cfb3d371af 100644
--- a/lib/libcrypto/ui/ui_lib.c
+++ b/lib/libcrypto/ui/ui_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ui_lib.c,v 1.53 2026/05/19 09:17:44 tb Exp $ */
+/* $OpenBSD: ui_lib.c,v 1.54 2026/05/19 09:23:36 tb Exp $ */
 /* Written by Richard Levitte (richard@levitte.org) for the OpenSSL
  * project 2001.
  */
@@ -95,7 +95,7 @@ struct ui_string_st {
 			const char *ok_chars; /* Input */
 			const char *cancel_chars; /* Input */
 		} boolean_data;
-	} _;
+	} u;
 
 #define OUT_STRING_FREEABLE 0x01
 	int flags;		/* flags for internal use */
@@ -134,9 +134,9 @@ free_string(UI_STRING *uis)
 		free((char *) uis->out_string);
 		switch (uis->type) {
 		case UIT_BOOLEAN:
-			free((char *)uis->_.boolean_data.action_desc);
-			free((char *)uis->_.boolean_data.ok_chars);
-			free((char *)uis->_.boolean_data.cancel_chars);
+			free((char *)uis->u.boolean_data.action_desc);
+			free((char *)uis->u.boolean_data.ok_chars);
+			free((char *)uis->u.boolean_data.cancel_chars);
 			break;
 		default:
 			break;
@@ -219,9 +219,9 @@ general_allocate_string(UI *ui, const char *prompt, int dup_prompt,
 	if ((s = general_allocate_prompt(prompt, dup_prompt, type, input_flags,
 	    result_buf)) == NULL)
 		goto err;
-	s->_.string_data.result_minsize = minsize;
-	s->_.string_data.result_maxsize = maxsize;
-	s->_.string_data.test_buf = test_buf;
+	s->u.string_data.result_minsize = minsize;
+	s->u.string_data.result_maxsize = maxsize;
+	s->u.string_data.test_buf = test_buf;
 
 	if (allocate_string_stack(ui) < 0)
 		goto err;
@@ -258,25 +258,25 @@ general_allocate_boolean(UI *ui, const char *prompt, const char *action_desc,
 
 	if (dup_strings) {
 		if (action_desc != NULL) {
-			if ((s->_.boolean_data.action_desc =
+			if ((s->u.boolean_data.action_desc =
 			    strdup(action_desc)) == NULL) {
 				UIerror(ERR_R_MALLOC_FAILURE);
 				goto err;
 			}
 		}
-		if ((s->_.boolean_data.ok_chars = strdup(ok_chars)) == NULL) {
+		if ((s->u.boolean_data.ok_chars = strdup(ok_chars)) == NULL) {
 			UIerror(ERR_R_MALLOC_FAILURE);
 			goto err;
 		}
-		if ((s->_.boolean_data.cancel_chars = strdup(cancel_chars)) ==
+		if ((s->u.boolean_data.cancel_chars = strdup(cancel_chars)) ==
 		    NULL) {
 			UIerror(ERR_R_MALLOC_FAILURE);
 			goto err;
 		}
 	} else {
-		s->_.boolean_data.action_desc = action_desc;
-		s->_.boolean_data.ok_chars = ok_chars;
-		s->_.boolean_data.cancel_chars = cancel_chars;
+		s->u.boolean_data.action_desc = action_desc;
+		s->u.boolean_data.ok_chars = ok_chars;
+		s->u.boolean_data.cancel_chars = cancel_chars;
 	}
 
 	if (allocate_string_stack(ui) < 0)
@@ -805,7 +805,7 @@ UI_get0_action_string(UI_STRING *uis)
 	switch (uis->type) {
 	case UIT_PROMPT:
 	case UIT_BOOLEAN:
-		return uis->_.boolean_data.action_desc;
+		return uis->u.boolean_data.action_desc;
 	default:
 		return NULL;
 	}
@@ -836,7 +836,7 @@ UI_get0_test_string(UI_STRING *uis)
 
 	switch (uis->type) {
 	case UIT_VERIFY:
-		return uis->_.string_data.test_buf;
+		return uis->u.string_data.test_buf;
 	default:
 		return NULL;
 	}
@@ -852,7 +852,7 @@ UI_get_result_minsize(UI_STRING *uis)
 	switch (uis->type) {
 	case UIT_PROMPT:
 	case UIT_VERIFY:
-		return uis->_.string_data.result_minsize;
+		return uis->u.string_data.result_minsize;
 	default:
 		return -1;
 	}
@@ -868,7 +868,7 @@ UI_get_result_maxsize(UI_STRING *uis)
 	switch (uis->type) {
 	case UIT_PROMPT:
 	case UIT_VERIFY:
-		return uis->_.string_data.result_maxsize;
+		return uis->u.string_data.result_maxsize;
 	default:
 		return -1;
 	}
@@ -889,22 +889,22 @@ UI_set_result(UI *ui, UI_STRING *uis, const char *result)
 	switch (uis->type) {
 	case UIT_PROMPT:
 	case UIT_VERIFY:
-		if (l < uis->_.string_data.result_minsize) {
+		if (l < uis->u.string_data.result_minsize) {
 			ui->flags |= UI_FLAG_REDOABLE;
 			UIerror(UI_R_RESULT_TOO_SMALL);
 			ERR_asprintf_error_data
 			    ("You must type in %d to %d characters",
-				uis->_.string_data.result_minsize,
-				uis->_.string_data.result_maxsize);
+				uis->u.string_data.result_minsize,
+				uis->u.string_data.result_maxsize);
 			return -1;
 		}
-		if (l > uis->_.string_data.result_maxsize) {
+		if (l > uis->u.string_data.result_maxsize) {
 			ui->flags |= UI_FLAG_REDOABLE;
 			UIerror(UI_R_RESULT_TOO_LARGE);
 			ERR_asprintf_error_data
 			    ("You must type in %d to %d characters",
-				uis->_.string_data.result_minsize,
-				uis->_.string_data.result_maxsize);
+				uis->u.string_data.result_minsize,
+				uis->u.string_data.result_maxsize);
 			return -1;
 		}
 		if (!uis->result_buf) {
@@ -912,7 +912,7 @@ UI_set_result(UI *ui, UI_STRING *uis, const char *result)
 			return -1;
 		}
 		strlcpy(uis->result_buf, result,
-		    uis->_.string_data.result_maxsize + 1);
+		    uis->u.string_data.result_maxsize + 1);
 		break;
 	case UIT_BOOLEAN:
 		if (!uis->result_buf) {
@@ -921,14 +921,14 @@ UI_set_result(UI *ui, UI_STRING *uis, const char *result)
 		}
 		uis->result_buf[0] = '\0';
 		for (p = result; *p; p++) {
-			if (strchr(uis->_.boolean_data.ok_chars, *p)) {
+			if (strchr(uis->u.boolean_data.ok_chars, *p)) {
 				uis->result_buf[0] =
-				    uis->_.boolean_data.ok_chars[0];
+				    uis->u.boolean_data.ok_chars[0];
 				break;
 			}
-			if (strchr(uis->_.boolean_data.cancel_chars, *p)) {
+			if (strchr(uis->u.boolean_data.cancel_chars, *p)) {
 				uis->result_buf[0] =
-				    uis->_.boolean_data.cancel_chars[0];
+				    uis->u.boolean_data.cancel_chars[0];
 				break;
 			}
 		}