diff --git a/lib/compress.js b/lib/compress.js
index a9e1da37..41e4f17f 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -2480,7 +2480,7 @@ merge(Compressor.prototype, {
     });
 
     function literals_in_boolean_context(self, compressor) {
-        if (compressor.option("booleans") && compressor.in_boolean_context()) {
+        if (compressor.option("booleans") && compressor.in_boolean_context() && !self.has_side_effects(compressor)) {
             return make_node(AST_True, self);
         }
         return self;