diff --git a/packages/stinst/parser/STCompiler.st b/packages/stinst/parser/STCompiler.st
index 620e019..a386c7e 100644
--- a/packages/stinst/parser/STCompiler.st
+++ b/packages/stinst/parser/STCompiler.st
@@ -793,6 +793,10 @@ indexed'' bytecode. The resulting stream is
     compileBoolean: aNode [
 	<category: 'compiling'>
 	| bc1 ret1 bc2 selector |
+	aNode arguments do: [ :each |
+		each isVariable ifTrue: [ aNode receiver acceptVisitor: self.
+        				  self compileMessage: aNode.
+					  ^ true ] ].
 	aNode arguments do: 
 		[:each | 
 		(each arguments isEmpty and: [each body temporaries isEmpty])