diff --git a/csv/_io.ts b/csv/_io.ts
index ebe145b5a..9f0db09b6 100644
--- a/csv/_io.ts
+++ b/csv/_io.ts
@@ -94,9 +94,7 @@ export async function parseRecord(
       if (!opt.lazyQuotes) {
         const j = field.indexOf(quote);
         if (j >= 0) {
-          const col = runeCount(
-            fullLine.slice(0, fullLine.length - line.slice(j).length),
-          );
+          const col = fullLine.length + j - line.length;
           throw new ParseError(startLine + 1, lineIndex, col, ERR_BARE_QUOTE);
         }
       }
@@ -134,9 +132,7 @@ export async function parseRecord(
             recordBuffer += quote;
           } else {
             // `"*` sequence (invalid non-escaped quote).
-            const col = runeCount(
-              fullLine.slice(0, fullLine.length - line.length - quoteLen),
-            );
+            const col = fullLine.length - line.length - quoteLen;
             throw new ParseError(startLine + 1, lineIndex, col, ERR_QUOTE);
           }
         } else if (line.length > 0 || !reader.isEOF()) {
@@ -149,7 +145,7 @@ export async function parseRecord(
           if (r === null) {
             // Abrupt end of file (EOF or error).
             if (!opt.lazyQuotes) {
-              const col = runeCount(fullLine);
+              const col = fullLine.length;
               throw new ParseError(startLine + 1, lineIndex, col, ERR_QUOTE);
             }
             fieldIndexes.push(recordBuffer.length);
@@ -159,7 +155,7 @@ export async function parseRecord(
         } else {
           // Abrupt end of file (EOF on error).
           if (!opt.lazyQuotes) {
-            const col = runeCount(fullLine);
+            const col = fullLine.length;
             throw new ParseError(startLine + 1, lineIndex, col, ERR_QUOTE);
           }
           fieldIndexes.push(recordBuffer.length);
@@ -177,11 +173,6 @@ export async function parseRecord(
   return result;
 }
 
-function runeCount(s: string): number {
-  // Array.from considers the surrogate pair.
-  return Array.from(s).length;
-}
-
 /**
  * A ParseError is returned for parsing errors.
  * Line numbers are 1-indexed and columns are 0-indexed.
diff --git a/csv/parse.ts b/csv/parse.ts
index acd6dcf89..e3d39cad5 100644
--- a/csv/parse.ts
+++ b/csv/parse.ts
@@ -79,11 +79,6 @@ class Parser {
       return [];
     }
 
-    function runeCount(s: string): number {
-      // Array.from considers the surrogate pair.
-      return Array.from(s).length;
-    }
-
     let lineIndex = startLine + 1;
 
     // line starting with comment character is ignored
@@ -113,9 +108,7 @@ class Parser {
         if (!this.#options.lazyQuotes) {
           const j = field.indexOf(quote);
           if (j >= 0) {
-            const col = runeCount(
-              fullLine.slice(0, fullLine.length - line.slice(j).length),
-            );
+            const col = fullLine.length + j - line.length;
             throw new ParseError(startLine + 1, lineIndex, col, ERR_BARE_QUOTE);
           }
         }
@@ -153,9 +146,7 @@ class Parser {
               recordBuffer += quote;
             } else {
               // `"*` sequence (invalid non-escaped quote).
-              const col = runeCount(
-                fullLine.slice(0, fullLine.length - line.length - quoteLen),
-              );
+              const col = fullLine.length - line.length - quoteLen;
               throw new ParseError(startLine + 1, lineIndex, col, ERR_QUOTE);
             }
           } else if (line.length > 0 || !(this.#isEOF())) {
@@ -168,7 +159,7 @@ class Parser {
             if (r === null) {
               // Abrupt end of file (EOF or error).
               if (!this.#options.lazyQuotes) {
-                const col = runeCount(fullLine);
+                const col = fullLine.length;
                 throw new ParseError(startLine + 1, lineIndex, col, ERR_QUOTE);
               }
               fieldIndexes.push(recordBuffer.length);
@@ -178,7 +169,7 @@ class Parser {
           } else {
             // Abrupt end of file (EOF on error).
             if (!this.#options.lazyQuotes) {
-              const col = runeCount(fullLine);
+              const col = fullLine.length;
               throw new ParseError(startLine + 1, lineIndex, col, ERR_QUOTE);
             }
             fieldIndexes.push(recordBuffer.length);