diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index e9f694c11..4d0010428 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -86,6 +86,8 @@ boost::optional<CompilerStack::Remapping> CompilerStack::parseRemapping(string c
 
 void CompilerStack::setRemappings(vector<Remapping> const& _remappings)
 {
+	if (m_stackState >= ParsingSuccessful)
+		BOOST_THROW_EXCEPTION(CompilerError() << errinfo_comment("Must set remappings before parsing."));
 	for (auto const& remapping: _remappings)
 		solAssert(!remapping.prefix.empty(), "");
 	m_remappings = _remappings;
@@ -93,10 +95,40 @@ void CompilerStack::setRemappings(vector<Remapping> const& _remappings)
 
 void CompilerStack::setEVMVersion(langutil::EVMVersion _version)
 {
-	solAssert(m_stackState < State::ParsingSuccessful, "Set EVM version after parsing.");
+	if (m_stackState >= ParsingSuccessful)
+		BOOST_THROW_EXCEPTION(CompilerError() << errinfo_comment("Must set EVM version before parsing."));
 	m_evmVersion = _version;
 }
 
+void CompilerStack::setLibraries(std::map<std::string, h160> const& _libraries)
+{
+	if (m_stackState >= ParsingSuccessful)
+		BOOST_THROW_EXCEPTION(CompilerError() << errinfo_comment("Must set libraries before parsing."));
+	m_libraries = _libraries;
+}
+
+void CompilerStack::setOptimiserSettings(bool _optimize, unsigned _runs)
+{
+	if (m_stackState >= ParsingSuccessful)
+		BOOST_THROW_EXCEPTION(CompilerError() << errinfo_comment("Must set optimiser settings before parsing."));
+	m_optimize = _optimize;
+	m_optimizeRuns = _runs;
+}
+
+void CompilerStack::useMetadataLiteralSources(bool _metadataLiteralSources)
+{
+	if (m_stackState >= ParsingSuccessful)
+		BOOST_THROW_EXCEPTION(CompilerError() << errinfo_comment("Must set use literal sources before parsing."));
+	m_metadataLiteralSources = _metadataLiteralSources;
+}
+
+void CompilerStack::addSMTLib2Response(h256 const& _hash, string const& _response)
+{
+	if (m_stackState >= ParsingSuccessful)
+		BOOST_THROW_EXCEPTION(CompilerError() << errinfo_comment("Must add SMTLib2 responses before parsing."));
+	m_smtlib2Responses[_hash] = _response;
+}
+
 void CompilerStack::reset(bool _keepSources)
 {
 	if (_keepSources)
diff --git a/libsolidity/interface/CompilerStack.h b/libsolidity/interface/CompilerStack.h
index 12a0a5e0c..ffae921ab 100644
--- a/libsolidity/interface/CompilerStack.h
+++ b/libsolidity/interface/CompilerStack.h
@@ -117,43 +117,39 @@ public:
 	static boost::optional<Remapping> parseRemapping(std::string const& _remapping);
 
 	/// Sets path remappings.
+	/// Must be set before parsing.
 	void setRemappings(std::vector<Remapping> const& _remappings);
 
 	/// Sets library addresses. Addresses are cleared iff @a _libraries is missing.
-	/// Will not take effect before running compile.
-	void setLibraries(std::map<std::string, h160> const& _libraries = std::map<std::string, h160>{})
-	{
-		m_libraries = _libraries;
-	}
+	/// Must be set before parsing.
+	void setLibraries(std::map<std::string, h160> const& _libraries = std::map<std::string, h160>{});
 
 	/// Changes the optimiser settings.
-	/// Will not take effect before running compile.
-	void setOptimiserSettings(bool _optimize, unsigned _runs = 200)
-	{
-		m_optimize = _optimize;
-		m_optimizeRuns = _runs;
-	}
+	/// Must be set before parsing.
+	void setOptimiserSettings(bool _optimize, unsigned _runs = 200);
 
 	/// Set the EVM version used before running compile.
 	/// When called without an argument it will revert to the default version.
+	/// Must be set before parsing.
 	void setEVMVersion(langutil::EVMVersion _version = langutil::EVMVersion{});
 
 	/// Sets the list of requested contract names. If empty, no filtering is performed and every contract
 	/// found in the supplied sources is compiled. Names are cleared iff @a _contractNames is missing.
-	void setRequestedContractNames(std::set<std::string> const& _contractNames = std::set<std::string>{})
-	{
+	void setRequestedContractNames(std::set<std::string> const& _contractNames = std::set<std::string>{}) {
 		m_requestedContractNames = _contractNames;
 	}
 
 	/// @arg _metadataLiteralSources When true, store sources as literals in the contract metadata.
-	void useMetadataLiteralSources(bool _metadataLiteralSources) { m_metadataLiteralSources = _metadataLiteralSources; }
+	/// Must be set before parsing.
+	void useMetadataLiteralSources(bool _metadataLiteralSources);
 
 	/// Adds a source object (e.g. file) to the parser. After this, parse has to be called again.
 	/// @returns true if a source object by the name already existed and was replaced.
 	bool addSource(std::string const& _name, std::string const& _content, bool _isLibrary = false);
 
 	/// Adds a response to an SMTLib2 query (identified by the hash of the query input).
-	void addSMTLib2Response(h256 const& _hash, std::string const& _response) { m_smtlib2Responses[_hash] = _response; }
+	/// Must be set before parsing.
+	void addSMTLib2Response(h256 const& _hash, std::string const& _response);
 
 	/// Parses all source units that were added
 	/// @returns false on error.
diff --git a/test/libsolidity/SolidityCompiler.cpp b/test/libsolidity/SolidityCompiler.cpp
index 0cc80dd82..57a7c8d1b 100644
--- a/test/libsolidity/SolidityCompiler.cpp
+++ b/test/libsolidity/SolidityCompiler.cpp
@@ -42,8 +42,8 @@ BOOST_AUTO_TEST_CASE(does_not_include_creation_time_only_internal_functions)
 			function f() internal { for (uint i = 0; i < 10; ++i) x += 3 + i; }
 		}
 	)";
-	BOOST_REQUIRE(success(sourceCode));
 	m_compiler.setOptimiserSettings(dev::test::Options::get().optimize);
+	BOOST_REQUIRE(success(sourceCode));
 	BOOST_REQUIRE_MESSAGE(m_compiler.compile(), "Compiling contract failed");
 	bytes const& creationBytecode = m_compiler.object("C").bytecode;
 	bytes const& runtimeBytecode = m_compiler.runtimeObject("C").bytecode;