diff --git a/libdevcore/Whiskers.cpp b/libdevcore/Whiskers.cpp
index 8a20f2cd7..c48c8d6f1 100644
--- a/libdevcore/Whiskers.cpp
+++ b/libdevcore/Whiskers.cpp
@@ -37,6 +37,7 @@ Whiskers::Whiskers(string _template):
 
 Whiskers& Whiskers::operator()(string _parameter, string _value)
 {
+	checkParameterValid(_parameter);
 	checkParameterUnknown(_parameter);
 	m_parameters[move(_parameter)] = move(_value);
 	return *this;
@@ -44,6 +45,7 @@ Whiskers& Whiskers::operator()(string _parameter, string _value)
 
 Whiskers& Whiskers::operator()(string _parameter, bool _value)
 {
+	checkParameterValid(_parameter);
 	checkParameterUnknown(_parameter);
 	m_conditions[move(_parameter)] = _value;
 	return *this;
@@ -54,7 +56,11 @@ Whiskers& Whiskers::operator()(
 	vector<map<string, string>> _values
 )
 {
+	checkParameterValid(_listParameter);
 	checkParameterUnknown(_listParameter);
+	for (auto const& element: _values)
+		for (auto const& val: element)
+			checkParameterValid(val.first);
 	m_listParameters[move(_listParameter)] = move(_values);
 	return *this;
 }
@@ -64,7 +70,17 @@ string Whiskers::render() const
 	return replace(m_template, m_parameters, m_conditions, m_listParameters);
 }
 
-void Whiskers::checkParameterUnknown(string const& _parameter)
+void Whiskers::checkParameterValid(string const& _parameter) const
+{
+	static boost::regex validParam("^" + paramRegex() + "$");
+	assertThrow(
+		boost::regex_match(_parameter, validParam),
+		WhiskersError,
+		"Parameter" + _parameter + " contains invalid characters."
+	);
+}
+
+void Whiskers::checkParameterUnknown(string const& _parameter) const
 {
 	assertThrow(
 		!m_parameters.count(_parameter),
@@ -91,7 +107,7 @@ string Whiskers::replace(
 )
 {
 	using namespace boost;
-	static regex listOrTag("<([^#/?!>]+)>|<#([^>]+)>(.*?)</\\2>|<\\?([^>]+)>(.*?)(<!\\4>(.*?))?</\\4>");
+	static regex listOrTag("<(" + paramRegex() + ")>|<#(" + paramRegex() + ")>(.*?)</\\2>|<\\?(" + paramRegex() + ")>(.*?)(<!\\4>(.*?))?</\\4>");
 	return regex_replace(_template, listOrTag, [&](match_results<string::const_iterator> _match) -> string
 	{
 		string tagName(_match[1]);
diff --git a/libdevcore/Whiskers.h b/libdevcore/Whiskers.h
index 7944358a0..ebe17b51c 100644
--- a/libdevcore/Whiskers.h
+++ b/libdevcore/Whiskers.h
@@ -85,7 +85,8 @@ public:
 	std::string render() const;
 
 private:
-	void checkParameterUnknown(std::string const& _parameter);
+	void checkParameterValid(std::string const& _parameter) const;
+	void checkParameterUnknown(std::string const& _parameter) const;
 
 	static std::string replace(
 		std::string const& _template,
@@ -94,6 +95,8 @@ private:
 		StringListMap const& _listParameters = StringListMap()
 	);
 
+	static std::string paramRegex() { return "[a-zA-Z0-9_$-]+"; }
+
 	/// Joins the two maps throwing an exception if two keys are equal.
 	static StringMap joinMaps(StringMap const& _a, StringMap const& _b);
 
diff --git a/test/libdevcore/Whiskers.cpp b/test/libdevcore/Whiskers.cpp
index 8a785774e..924f2efd0 100644
--- a/test/libdevcore/Whiskers.cpp
+++ b/test/libdevcore/Whiskers.cpp
@@ -116,11 +116,11 @@ BOOST_AUTO_TEST_CASE(conditional_plus_list)
 
 BOOST_AUTO_TEST_CASE(complicated_replacement)
 {
-	string templ = "a <b> x <complicated> \n <nes<ted>>.";
+	string templ = "a <b> x <complicated> \n <nested>>.";
 	string result = Whiskers(templ)
 		("b", "BE")
 		("complicated", "CO<M>PL")
-		("nes<ted", "NEST")
+		("nested", "NEST")
 		.render();
 	BOOST_CHECK_EQUAL(result, "a BE x CO<M>PL \n NEST>.");
 }
@@ -180,6 +180,20 @@ BOOST_AUTO_TEST_CASE(parameter_collision)
 	BOOST_CHECK_THROW(m.render(), WhiskersError);
 }
 
+BOOST_AUTO_TEST_CASE(invalid_param)
+{
+	string templ = "a <b >";
+	Whiskers m(templ);
+	BOOST_CHECK_THROW(m("b ", "X"), WhiskersError);
+}
+
+BOOST_AUTO_TEST_CASE(invalid_param_rendered)
+{
+	string templ = "a <b >";
+	Whiskers m(templ);
+	BOOST_CHECK_EQUAL(m.render(), templ);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }