diff --git a/libsolidity/Types.h b/libsolidity/Types.h
index 718f347f8..dd89f311d 100644
--- a/libsolidity/Types.h
+++ b/libsolidity/Types.h
@@ -184,7 +184,7 @@ private:
 class BoolType: public Type
 {
 public:
-	explicit BoolType() {}
+	BoolType() {}
 	virtual Category getCategory() const { return Category::BOOL; }
 	virtual bool isExplicitlyConvertibleTo(Type const& _convertTo) const override;
 	virtual bool acceptsBinaryOperator(Token::Value _operator) const override