diff --git a/libinterp/parse-tree/lex.ll b/libinterp/parse-tree/lex.ll
--- a/libinterp/parse-tree/lex.ll
+++ b/libinterp/parse-tree/lex.ll
@@ -911,53 +911,47 @@ ANY_INCLUDING_NL (.|{NL})
     curr_lexer->string_text += static_cast<unsigned char> (result);
   }
 
-<DQ_STRING_START>"\\a" {
-    curr_lexer->lexer_debug ("<DQ_STRING_START>\"\\\\a\"");
-
-    curr_lexer->current_input_column += yyleng;
-    curr_lexer->string_text += '\a';
-  }
-
-<DQ_STRING_START>"\\b" {
-    curr_lexer->lexer_debug ("<DQ_STRING_START>\"\\\\b\"");
-
-    curr_lexer->current_input_column += yyleng;
-    curr_lexer->string_text += '\b';
-  }
-
-<DQ_STRING_START>"\\f" {
-    curr_lexer->lexer_debug ("<DQ_STRING_START>\"\\\\f\"");
+<DQ_STRING_START>\\[abfnrtv] {
+    curr_lexer->lexer_debug ("<DQ_STRING_START>\\\\[abfnrtv]");
+
+    static const char *msg = "the behavior of backslash escape sequences in double-quoted strings will change in a future version of Octave; please see the NEWS file for more information";
+
+    warning_with_id ("Octave:backslash-escape-compatibility", "%s", msg);
 
     curr_lexer->current_input_column += yyleng;
-    curr_lexer->string_text += '\f';
-  }
-
-<DQ_STRING_START>"\\n" {
-    curr_lexer->lexer_debug ("<DQ_STRING_START>\"\\\\n\"");
-
-    curr_lexer->current_input_column += yyleng;
-    curr_lexer->string_text += '\n';
-  }
-
-<DQ_STRING_START>"\\r" {
-    curr_lexer->lexer_debug ("<DQ_STRING_START>\"\\\\r\"");
-
-    curr_lexer->current_input_column += yyleng;
-    curr_lexer->string_text += '\r';
-  }
-
-<DQ_STRING_START>"\\t" {
-    curr_lexer->lexer_debug ("<DQ_STRING_START>\"\\\\t\"");
-
-    curr_lexer->current_input_column += yyleng;
-    curr_lexer->string_text += '\t';
-  }
-
-<DQ_STRING_START>"\\v" {
-    curr_lexer->lexer_debug ("<DQ_STRING_START>\"\\\\v\"");
-
-    curr_lexer->current_input_column += yyleng;
-    curr_lexer->string_text += '\v';
+    switch (yytext[1])
+      {
+      case 'a':
+        curr_lexer->string_text += '\a';
+        break;
+
+      case 'b':
+        curr_lexer->string_text += '\b';
+        break;
+
+      case 'f':
+        curr_lexer->string_text += '\f';
+        break;
+
+      case 'n':
+        curr_lexer->string_text += '\n';
+        break;
+
+      case 'r':
+        curr_lexer->string_text += '\r';
+        break;
+
+      case 't':
+        curr_lexer->string_text += '\t';
+        break;
+
+      case 'v':
+        curr_lexer->string_text += '\v';
+        break;
+
+      default:
+        panic_impossible ();
+      }
   }
 
 <DQ_STRING_START>(\.\.\.){S}*{NL} {