diff --git a/packages/core-components/src/components/LogViewer/LogLine.tsx b/packages/core-components/src/components/LogViewer/LogLine.tsx
index 4f888fc68e..c258c27655 100644
--- a/packages/core-components/src/components/LogViewer/LogLine.tsx
+++ b/packages/core-components/src/components/LogViewer/LogLine.tsx
@@ -177,8 +177,7 @@ export function LogLine({
 
   useEffect(() => {
     if (lineRef.current && setRowHeight) {
-      // lineNumber is 1-based but height index is 0-based
-      setRowHeight(line.lineNumber - 1, lineRef.current.offsetHeight);
+      setRowHeight(line.lineNumber, lineRef.current.offsetHeight);
     }
   }, [line.lineNumber, setRowHeight]);
 
diff --git a/packages/core-components/src/components/LogViewer/RealLogViewer.tsx b/packages/core-components/src/components/LogViewer/RealLogViewer.tsx
index 1647e9a925..c3b9d67773 100644
--- a/packages/core-components/src/components/LogViewer/RealLogViewer.tsx
+++ b/packages/core-components/src/components/LogViewer/RealLogViewer.tsx
@@ -87,7 +87,8 @@ export function RealLogViewer(props: RealLogViewerProps) {
   function setRowHeight(index: number, size: number) {
     if (shouldTextWrap && listInstance) {
       (listInstance as VariableSizeList<AnsiLine[]>).resetAfterIndex(0);
-      heights.current = { ...heights.current, [index]: size };
+      // lineNumber is 1-based but index is 0-based
+      heights.current = { ...heights.current, [index - 1]: size };
     }
   }