diff --git a/mlir/lib/Tools/mlir-lsp-server/MLIRServer.cpp b/mlir/lib/Tools/mlir-lsp-server/MLIRServer.cpp
--- a/mlir/lib/Tools/mlir-lsp-server/MLIRServer.cpp
+++ b/mlir/lib/Tools/mlir-lsp-server/MLIRServer.cpp
@@ -57,10 +57,15 @@
     return llvm::None;
   }
 
-  lsp::Position position;
-  position.line = loc.getLine() - 1;
-  position.character = loc.getColumn();
-  return lsp::Location{*sourceURI, lsp::Range(position)};
+  lsp::Position positionStart;
+  positionStart.line = loc.getLine() - 1;
+  positionStart.character = loc.getColumn();
+  // FIXME: Arbitrarily choose an end up point 3 characters post start for
+  // frontends where underlining only happens if the range is non-empty. This
+  // does not consider actual file contents (incl new lines).
+  lsp::Position positionEnd(positionStart);
+  positionEnd.character += 3;
+  return lsp::Location{*sourceURI, lsp::Range(positionStart, positionEnd)};
 }
 
 /// Returns a language server location from the given MLIR location, or None if
diff --git a/mlir/test/mlir-lsp-server/diagnostics.test b/mlir/test/mlir-lsp-server/diagnostics.test
--- a/mlir/test/mlir-lsp-server/diagnostics.test
+++ b/mlir/test/mlir-lsp-server/diagnostics.test
@@ -15,7 +15,7 @@
 // CHECK-NEXT:         "message": "custom op 'func' expected valid '@'-identifier for symbol name",
 // CHECK-NEXT:         "range": {
 // CHECK-NEXT:           "end": {
-// CHECK-NEXT:             "character": 6,
+// CHECK-NEXT:             "character": 9,
 // CHECK-NEXT:             "line": 0
 // CHECK-NEXT:           },
 // CHECK-NEXT:           "start": {