diff --git a/server/src/lfortran-accessors.ts b/server/src/lfortran-accessors.ts
index 99c3fb5..e499256 100644
--- a/server/src/lfortran-accessors.ts
+++ b/server/src/lfortran-accessors.ts
@@ -508,6 +508,9 @@ export class LFortranCLIAccessor implements LFortranAccessor {
           for (let i = 0; i < k; i++) {
             const diagnostic: Diagnostic = results.diagnostics[i];
             diagnostic.source = "lfortran-lsp";
+            if (!uri.includes(".ts")) {
+              diagnostic.range.start.line--;
+            }
             diagnostic.range.start.character--;
             diagnostics.push(diagnostic);
           }