diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 71b8505b32..85e2a902a2 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1190,14 +1190,14 @@ reportDependentObjects(const ObjectAddresses *targetObjects,
 					(errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
 					 errmsg("cannot drop %s because other objects depend on it",
 							getObjectDescription(origObject, false)),
-					 errdetail("%s", clientdetail.data),
+					 errdetail_internal("%s", clientdetail.data),
 					 errdetail_log("%s", logdetail.data),
 					 errhint("Use DROP ... CASCADE to drop the dependent objects too.")));
 		else
 			ereport(ERROR,
 					(errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
 					 errmsg("cannot drop desired object(s) because other objects depend on them"),
-					 errdetail("%s", clientdetail.data),
+					 errdetail_internal("%s", clientdetail.data),
 					 errdetail_log("%s", logdetail.data),
 					 errhint("Use DROP ... CASCADE to drop the dependent objects too.")));
 	}
@@ -1208,7 +1208,7 @@ reportDependentObjects(const ObjectAddresses *targetObjects,
 							   "drop cascades to %d other objects",
 							   numReportedClient + numNotReportedClient,
 							   numReportedClient + numNotReportedClient),
-				 errdetail("%s", clientdetail.data),
+				 errdetail_internal("%s", clientdetail.data),
 				 errdetail_log("%s", logdetail.data)));
 	}
 	else if (numReportedClient == 1)
diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index d2ed70ee3d..473c72eae5 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -580,7 +580,7 @@ check_simple_rowfilter_expr_walker(Node *node, ParseState *pstate)
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("invalid publication WHERE expression"),
-				 errdetail("%s", errdetail_msg),
+				 errdetail_internal("%s", errdetail_msg),
 				 parser_errposition(pstate, exprLocation(node))));
 
 	return expression_tree_walker(node, check_simple_rowfilter_expr_walker,
diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index 984305ba31..cba8e1979b 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -521,7 +521,7 @@ AlterRole(ParseState *pstate, AlterRoleStmt *stmt)
 	Oid			roleid;
 
 	check_rolespec_name(stmt->role,
-						"Cannot alter reserved roles.");
+						_("Cannot alter reserved roles."));
 
 	/* Extract options from the statement node tree */
 	foreach(option, stmt->options)
@@ -835,7 +835,7 @@ AlterRoleSet(AlterRoleSetStmt *stmt)
 	if (stmt->role)
 	{
 		check_rolespec_name(stmt->role,
-							"Cannot alter reserved roles.");
+							_("Cannot alter reserved roles."));
 
 		roletuple = get_rolespec_tuple(stmt->role);
 		roleform = (Form_pg_authid) GETSTRUCT(roletuple);
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 772c04155c..5b7236abc9 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -5309,7 +5309,7 @@ get_rolespec_name(const RoleSpec *role)
 
 /*
  * Given a RoleSpec, throw an error if the name is reserved, using detail_msg,
- * if provided.
+ * if provided (which must be already translated).
  *
  * If node is NULL, no error is thrown.  If detail_msg is NULL then no detail
  * message is provided.
@@ -5330,7 +5330,7 @@ check_rolespec_name(const RoleSpec *role, const char *detail_msg)
 					(errcode(ERRCODE_RESERVED_NAME),
 					 errmsg("role name \"%s\" is reserved",
 							role->rolename),
-					 errdetail("%s", detail_msg)));
+					 errdetail_internal("%s", detail_msg)));
 		else
 			ereport(ERROR,
 					(errcode(ERRCODE_RESERVED_NAME),
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 177b1c5e3f..ccc3279575 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -615,13 +615,13 @@ json_ereport_error(JsonParseErrorType error, JsonLexContext *lex)
 		ereport(ERROR,
 				(errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
 				 errmsg("unsupported Unicode escape sequence"),
-				 errdetail("%s", json_errdetail(error, lex)),
+				 errdetail_internal("%s", json_errdetail(error, lex)),
 				 report_json_context(lex)));
 	else
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 				 errmsg("invalid input syntax for type %s", "json"),
-				 errdetail("%s", json_errdetail(error, lex)),
+				 errdetail_internal("%s", json_errdetail(error, lex)),
 				 report_json_context(lex)));
 }
 
diff --git a/src/common/jsonapi.c b/src/common/jsonapi.c
index 98e4ef0942..90abe2687f 100644
--- a/src/common/jsonapi.c
+++ b/src/common/jsonapi.c
@@ -1057,11 +1057,11 @@ extract_token(JsonLexContext *lex)
 }
 
 /*
- * Construct a detail message for a JSON error.
+ * Construct an (already translated) detail message for a JSON error.
  *
  * Note that the error message generated by this routine may not be
  * palloc'd, making it unsafe for frontend code as there is no way to
- * know if this can be safery pfree'd or not.
+ * know if this can be safely pfree'd or not.
  */
 char *
 json_errdetail(JsonParseErrorType error, JsonLexContext *lex)