diff --git a/packages/ts-plugin/src/index.ts b/packages/ts-plugin/src/index.ts
index 68f2f40..30f03f8 100644
--- a/packages/ts-plugin/src/index.ts
+++ b/packages/ts-plugin/src/index.ts
@@ -232,20 +232,98 @@ const boot: tslib.server.PluginModuleFactory = ({ typescript: ts }) => {
         ts.createSourceFile = createSourceFile;
     }
 
+    {
+        const oldUpdateSourceFile = ts.updateSourceFile;
+
+        function commonPrefixLength(a: string, b: string): number {
+            const limit = Math.min(a.length, b.length);
+            for (let i = 0; i < limit; i++) {
+                if (a[i] !== b[i]) return i;
+            }
+            return limit;
+        }
+
+        function commonSuffixLength(a: string, b: string): number {
+            const limit = Math.min(a.length, b.length);
+            for (let i = 0; i < limit; i++) {
+                if (a[a.length - i - 1] !== b[b.length - i - 1]) return i;
+            }
+            return limit;
+        }
+
+        function updateSourceFile(
+            sourceFile: ts.SourceFile,
+            newText: string,
+            textChangeRange: ts.TextChangeRange,
+            aggressiveChecks?: boolean,
+        ): ts.SourceFile {
+            return withFileName(
+                sourceFile.fileName,
+                () => oldUpdateSourceFile(sourceFile, newText, textChangeRange, aggressiveChecks),
+                (fx) => {
+                    const oldInfo = fx.info;
+                    return expandFile(
+                        sourceFile.fileName,
+                        oldInfo.originalSource,
+                        (newExpandedText) => {
+                            const oldExpandedText = oldInfo.sourceFile.text;
+                            if (oldExpandedText === newExpandedText) {
+                                // console.log('updateSourceFile', 'no change');
+                                return oldInfo.sourceFile;
+                            } else {
+                                const prefix = commonPrefixLength(oldExpandedText, newExpandedText);
+                                const suffix =
+                                    commonSuffixLength(oldExpandedText.substring(prefix),
+                                                       newExpandedText.substring(prefix));
+                                const newChangeRange = {
+                                    span: {
+                                        start: prefix,
+                                        length: oldExpandedText.length - prefix - suffix,
+                                    },
+                                    newLength: newExpandedText.length - prefix - suffix,
+                                } satisfies ts.TextChangeRange;
+                                // console.log('updateSourceFile', JSON.stringify({
+                                //     oldSyndicateText: oldInfo.originalSource,
+                                //     newSyndicateText: newText,
+                                //     oldExpandedText,
+                                //     newExpandedText,
+                                //     oldLength: oldExpandedText.length,
+                                //     newLength: newExpandedText.length,
+                                //     oldChangeRange: textChangeRange,
+                                //     newChangeRange,
+                                //     prefix,
+                                //     suffix,
+                                // }, void 0, 2));
+                                return oldUpdateSourceFile(
+                                    sourceFile, newExpandedText, newChangeRange, aggressiveChecks);
+                            }
+                        });
+                });
+        }
+
+        ts.updateSourceFile = updateSourceFile;
+    }
+
     {
         const oldEditContent = ts.server.ScriptInfo.prototype.editContent;
         ts.server.ScriptInfo.prototype.editContent =
             function (start: number, end: number, newText: string): void {
-                // console.log('SyndicateScriptInfo.editContent', this.fileName, start, end, newText);
+                // console.log('SyndicateScriptInfo.editContent', JSON.stringify({
+                //     fileName: this.fileName,
+                //     start,
+                //     end,
+                //     newText,
+                //     oldText: (this as any).textStorage.text ?? ["MISSING"],
+                // }, void 0, 2));
                 withFileName(this.fileName,
-                             () => oldEditContent(start, end, newText),
+                             () => oldEditContent.call(this, start, end, newText),
                              (fx) => {
                                  const info = fx.info;
                                  const revised = info.originalSource.substring(0, start) +
                                      newText +
                                      info.originalSource.substring(end);
                                  info.originalSource = revised;
-                                 this.open(revised);
+                                 oldEditContent.call(this, start, end, newText);
                              });
             };
     }