diff --git a/grammar.js b/grammar.js
index ffb193c..d4d6942 100644
--- a/grammar.js
+++ b/grammar.js
@@ -71,7 +71,7 @@ const PREC = {
   // #
   // NOTE: If we don't put comments at a negative rank, then `"#"` will treat the `#` as
   // the start of a comment rather than being part of the string.
-  COMMENT: { ASSOC: prec, RANK: -1},
+  COMMENT: { ASSOC: prec, RANK: -1 },
 
   // {, (
   // NOTE: If we understand correctly, brace and parenthesis blocks are given the same
@@ -237,8 +237,8 @@ module.exports = grammar({
     // Top-level rules.
     // The zero width `$._start` ensures that `program` starts at `(0, 0)`.
     program: $ => seq(
-        $._start,
-        repeat(choice($._expression, $._semicolon, $._newline))
+      $._start,
+      repeat(choice($._expression, $._semicolon, $._newline))
     ),
 
     // Function definitions.
@@ -730,7 +730,7 @@ module.exports = grammar({
     ),
 
     // Comments.
-    comment: $ => token(withPrec(PREC.COMMENT, /#.*/)),
+    comment: $ => token(withPrec(PREC.COMMENT, seq('#', /[^\r\n]*/))),
 
     // Commas. We include these in the AST so we can figure out the
     // argument call position. This is necessary given how R tolerates
diff --git a/src/grammar.json b/src/grammar.json
index b3cb825..5fb3d51 100644
--- a/src/grammar.json
+++ b/src/grammar.json
@@ -2812,8 +2812,17 @@
         "type": "PREC",
         "value": -1,
         "content": {
-          "type": "PATTERN",
-          "value": "#.*"
+          "type": "SEQ",
+          "members": [
+            {
+              "type": "STRING",
+              "value": "#"
+            },
+            {
+              "type": "PATTERN",
+              "value": "[^\\r\\n]*"
+            }
+          ]
         }
       }
     },
diff --git a/src/parser.c b/src/parser.c
index 9413479..7beca71 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -3685,18 +3685,18 @@ static bool ts_lex(TSLexer *lexer, TSStateId state) {
       END_STATE();
     case 3:
       if (lookahead == '"') ADVANCE(73);
-      if (lookahead == '#') ADVANCE(77);
+      if (lookahead == '#') ADVANCE(78);
       if (lookahead == '\\') ADVANCE(8);
       if (('\t' <= lookahead && lookahead <= '\r') ||
-          lookahead == ' ') ADVANCE(78);
+          lookahead == ' ') ADVANCE(77);
       if (lookahead != 0) ADVANCE(79);
       END_STATE();
     case 4:
-      if (lookahead == '#') ADVANCE(74);
+      if (lookahead == '#') ADVANCE(75);
       if (lookahead == '\'') ADVANCE(72);
       if (lookahead == '\\') ADVANCE(8);
       if (('\t' <= lookahead && lookahead <= '\r') ||
-          lookahead == ' ') ADVANCE(75);
+          lookahead == ' ') ADVANCE(74);
       if (lookahead != 0) ADVANCE(76);
       END_STATE();
     case 5:
@@ -4004,19 +4004,20 @@ static bool ts_lex(TSLexer *lexer, TSStateId state) {
       END_STATE();
     case 74:
       ACCEPT_TOKEN(aux_sym__single_quoted_string_content_token1);
-      if (lookahead == '\n') ADVANCE(76);
+      if (lookahead == '#') ADVANCE(75);
+      if (('\t' <= lookahead && lookahead <= '\r') ||
+          lookahead == ' ') ADVANCE(74);
       if (lookahead != 0 &&
           lookahead != '\'' &&
-          lookahead != '\\') ADVANCE(74);
+          lookahead != '\\') ADVANCE(76);
       END_STATE();
     case 75:
       ACCEPT_TOKEN(aux_sym__single_quoted_string_content_token1);
-      if (lookahead == '#') ADVANCE(74);
-      if (('\t' <= lookahead && lookahead <= '\r') ||
-          lookahead == ' ') ADVANCE(75);
+      if (lookahead == '\n' ||
+          lookahead == '\r') ADVANCE(76);
       if (lookahead != 0 &&
           lookahead != '\'' &&
-          lookahead != '\\') ADVANCE(76);
+          lookahead != '\\') ADVANCE(75);
       END_STATE();
     case 76:
       ACCEPT_TOKEN(aux_sym__single_quoted_string_content_token1);
@@ -4026,20 +4027,21 @@ static bool ts_lex(TSLexer *lexer, TSStateId state) {
       END_STATE();
     case 77:
       ACCEPT_TOKEN(aux_sym__double_quoted_string_content_token1);
-      if (lookahead == '\n') ADVANCE(79);
+      if (lookahead == '#') ADVANCE(78);
+      if (('\t' <= lookahead && lookahead <= '\r') ||
+          lookahead == ' ') ADVANCE(77);
       if (lookahead != 0 &&
           lookahead != '"' &&
-          lookahead != '\\') ADVANCE(77);
+          lookahead != '#' &&
+          lookahead != '\\') ADVANCE(79);
       END_STATE();
     case 78:
       ACCEPT_TOKEN(aux_sym__double_quoted_string_content_token1);
-      if (lookahead == '#') ADVANCE(77);
-      if (('\t' <= lookahead && lookahead <= '\r') ||
-          lookahead == ' ') ADVANCE(78);
+      if (lookahead == '\n' ||
+          lookahead == '\r') ADVANCE(79);
       if (lookahead != 0 &&
           lookahead != '"' &&
-          lookahead != '#' &&
-          lookahead != '\\') ADVANCE(79);
+          lookahead != '\\') ADVANCE(78);
       END_STATE();
     case 79:
       ACCEPT_TOKEN(aux_sym__double_quoted_string_content_token1);
@@ -4136,7 +4138,8 @@ static bool ts_lex(TSLexer *lexer, TSStateId state) {
     case 97:
       ACCEPT_TOKEN(sym_comment);
       if (lookahead != 0 &&
-          lookahead != '\n') ADVANCE(97);
+          lookahead != '\n' &&
+          lookahead != '\r') ADVANCE(97);
       END_STATE();
     case 98:
       ACCEPT_TOKEN(sym_comma);