diff --git a/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java b/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java
index 670c15c6e..390824005 100644
--- a/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java
+++ b/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java
@@ -182,7 +182,7 @@ public class Renderer implements RenderingManager {
     private void renderRuntimeString() throws IOException {
         MethodReference stringCons = new MethodReference(String.class, "<init>", char[].class, void.class);
         writer.append("function $rt_str(str) {").indent().softNewLine();
-        writer.append("if (str===null){").indent().softNewLine();
+        writer.append("if (str == null) {").indent().softNewLine();
         writer.append("return null;").softNewLine();
         writer.outdent().append("}").softNewLine();
         writer.append("var characters = $rt_createCharArray(str.length);").softNewLine();
diff --git a/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java b/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java
index 0925e8ae0..c3fc58b11 100644
--- a/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java
+++ b/core/src/main/java/org/teavm/backend/javascript/rendering/StatementRenderer.java
@@ -458,7 +458,7 @@ public class StatementRenderer implements ExprVisitor, StatementVisitor {
                     ? currentMethod.getVariables().get(index)
                     : null;
             if (variable != null && variable.getName() != null) {
-                String result = RenderingUtil.escapeName(variable.getName());
+                String result = "$" + RenderingUtil.escapeName(variable.getName());
                 if (keywords.contains(result) || !usedVariableNames.add(result)) {
                     String base = result;
                     int suffix = 0;