diff --git a/parse.y b/parse.y
index 616b2fe4f4..76386e47ed 100644
--- a/parse.y
+++ b/parse.y
@@ -5331,7 +5331,7 @@ string_content	: tSTRING_CONTENT
                         $<num>$ = p->heredoc_indent;
                         p->heredoc_indent = 0;
                     }
-                  compstmt tSTRING_DEND
+                  compstmt string_dend
                     {
                         COND_POP();
                         CMDARG_POP();
@@ -5348,6 +5348,10 @@ string_content	: tSTRING_CONTENT
                     }
                 ;
 
+string_dend	: tSTRING_DEND
+                | END_OF_INPUT
+                ;
+
 string_dvar	: tGVAR
                     {
                     /*%%%*/
diff --git a/test/ripper/test_lexer.rb b/test/ripper/test_lexer.rb
index 8e8a616627..92587ae4c0 100644
--- a/test/ripper/test_lexer.rb
+++ b/test/ripper/test_lexer.rb
@@ -264,4 +264,13 @@ world"
     CODE
     assert_equal(code, Ripper.tokenize(code).join(""), bug)
   end
+
+  def test_heredoc_unterminated_interpolation
+    code = <<~'HEREDOC'
+    <<A+1
+    #{
+    HEREDOC
+
+    assert_include(Ripper.tokenize(code).join(""), "+1")
+  end
 end
diff --git a/test/ruby/test_parse.rb b/test/ruby/test_parse.rb
index 71507575a7..099050dc8d 100644
--- a/test/ruby/test_parse.rb
+++ b/test/ruby/test_parse.rb
@@ -1121,6 +1121,15 @@ x = __ENCODING__
     assert_equal v1, v3
   end
 
+  def test_heredoc_unterminated_interpolation
+    code = <<~'HEREDOC'
+    <<A+1
+    #{
+    HEREDOC
+
+    assert_syntax_error(code, /can't find string "A"/)
+  end
+
   def test_unexpected_token_error
     assert_syntax_error('"x"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx', /unexpected/)
   end