diff --git a/core/src/main/java/org/teavm/ast/optimization/ExpressionSideEffectDecomposer.java b/core/src/main/java/org/teavm/ast/optimization/ExpressionSideEffectDecomposer.java
index 74146a144..1c30d56d1 100644
--- a/core/src/main/java/org/teavm/ast/optimization/ExpressionSideEffectDecomposer.java
+++ b/core/src/main/java/org/teavm/ast/optimization/ExpressionSideEffectDecomposer.java
@@ -16,6 +16,8 @@
 package org.teavm.ast.optimization;
 
 import java.util.List;
+import org.teavm.ast.BinaryExpr;
+import org.teavm.ast.BinaryOperation;
 import org.teavm.ast.ConditionalExpr;
 import org.teavm.ast.ConditionalStatement;
 import org.teavm.ast.InvocationExpr;
@@ -47,4 +49,13 @@ public class ExpressionSideEffectDecomposer extends RecursiveVisitor {
     public void visit(NewExpr expr) {
         target.add(Statement.assign(null, expr));
     }
+
+    @Override
+    public void visit(BinaryExpr expr) {
+        if (expr.getOperation() == BinaryOperation.AND || expr.getOperation() == BinaryOperation.OR) {
+            target.add(Statement.assign(null, expr));
+        } else {
+            super.visit(expr);
+        }
+    }
 }
diff --git a/core/src/main/java/org/teavm/ast/optimization/OptimizingVisitor.java b/core/src/main/java/org/teavm/ast/optimization/OptimizingVisitor.java
index d81b770e0..f1f421c59 100644
--- a/core/src/main/java/org/teavm/ast/optimization/OptimizingVisitor.java
+++ b/core/src/main/java/org/teavm/ast/optimization/OptimizingVisitor.java
@@ -766,6 +766,9 @@ class OptimizingVisitor implements StatementVisitor, ExprVisitor {
 
     private void normalizeConditional(ConditionalStatement stmt) {
         if (stmt.getConsequent().isEmpty()) {
+            if (stmt.getAlternative().isEmpty()) {
+                return;
+            }
             stmt.getConsequent().addAll(stmt.getAlternative());
             stmt.getAlternative().clear();
             stmt.setCondition(ExprOptimizer.invert(stmt.getCondition()));