diff --git a/CompilerContext.h b/CompilerContext.h
index dbf3dcd4f..573e0b576 100644
--- a/CompilerContext.h
+++ b/CompilerContext.h
@@ -98,7 +98,7 @@ public:
 	eth::AssemblyItem appendJumpToNew() { return m_asm.appendJump().tag(); }
 	/// Appends a JUMP to a tag already on the stack
 	CompilerContext&  appendJump(eth::AssemblyItem::JumpType _jumpType = eth::AssemblyItem::JumpType::Ordinary);
-	/// Appends a JUMP to an "ErrorTag"
+	/// Returns an "ErrorTag"
 	eth::AssemblyItem errorTag() { return m_asm.errorTag(); }
 	/// Appends a JUMP to a specific tag
 	CompilerContext& appendJumpTo(eth::AssemblyItem const& _tag) { m_asm.appendJump(_tag); return *this; }
diff --git a/ExpressionCompiler.cpp b/ExpressionCompiler.cpp
index 063af7ce6..c8aece85a 100644
--- a/ExpressionCompiler.cpp
+++ b/ExpressionCompiler.cpp
@@ -1104,8 +1104,9 @@ void ExpressionCompiler::appendExternalFunctionCall(
 	else
 		m_context << eth::Instruction::CALL;
 
+	//Propagate error condition (if CALL pushes 0 on stack).
 	m_context << eth::Instruction::ISZERO;
-	auto tag = m_context.appendConditionalJumpTo(m_context.errorTag());// if CALL leaves 0.
+	auto tag = m_context.appendConditionalJumpTo(m_context.errorTag());
 
 	if (_functionType.valueSet())
 		m_context << eth::Instruction::POP;