diff --git a/core/src/main/java/org/teavm/backend/javascript/rendering/RenderingContext.java b/core/src/main/java/org/teavm/backend/javascript/rendering/RenderingContext.java
index 4857219b4..5fbd47cb2 100644
--- a/core/src/main/java/org/teavm/backend/javascript/rendering/RenderingContext.java
+++ b/core/src/main/java/org/teavm/backend/javascript/rendering/RenderingContext.java
@@ -155,6 +155,8 @@ public class RenderingContext {
             }
         } else if (cst instanceof Character) {
             return Integer.toString((Character) cst);
+        } else if (cst instanceof Boolean) {
+            return (Boolean) cst ? "1" : "0";
         } else {
             return cst.toString();
         }