diff --git a/libyul/AsmAnalysis.cpp b/libyul/AsmAnalysis.cpp
index 7574ea506..12882e2ba 100644
--- a/libyul/AsmAnalysis.cpp
+++ b/libyul/AsmAnalysis.cpp
@@ -337,7 +337,8 @@ bool AsmAnalyzer::operator()(FunctionCall const& _funCall)
 		}
 	)))
 	{
-		m_errorReporter.declarationError(_funCall.functionName.location, "Function not found.");
+		if (!warnOnInstructions(_funCall.functionName.name.str(), _funCall.functionName.location))
+			m_errorReporter.declarationError(_funCall.functionName.location, "Function not found.");
 		success = false;
 	}
 	if (success)
@@ -653,7 +654,39 @@ void AsmAnalyzer::expectValidType(string const& type, SourceLocation const& _loc
 		);
 }
 
-void AsmAnalyzer::warnOnInstructions(dev::eth::Instruction _instr, SourceLocation const& _location)
+// FIXME: copy'n'paste from AsmParser. make it more general (by putting it into dev::eth namespace)
+std::map<string, dev::eth::Instruction> const& instructions()
+{
+	// Allowed instructions, lowercase names.
+	static map<string, dev::eth::Instruction> s_instructions;
+	if (s_instructions.empty())
+	{
+		for (auto const& instruction: dev::eth::c_instructions)
+		{
+			if (
+				instruction.second == dev::eth::Instruction::JUMPDEST ||
+				dev::eth::isPushInstruction(instruction.second)
+			)
+				continue;
+			string name = instruction.first;
+			transform(name.begin(), name.end(), name.begin(), [](unsigned char _c) { return tolower(_c); });
+			s_instructions[name] = instruction.second;
+		}
+	}
+	return s_instructions;
+}
+
+bool AsmAnalyzer::warnOnInstructions(std::string const& _instructionIdentifier, langutil::SourceLocation const& _location)
+{
+	auto const& instructionMap = instructions();
+	auto const identifier = boost::to_lower_copy(_instructionIdentifier);
+	if (auto const i = instructionMap.find(identifier); i != instructionMap.end())
+		return warnOnInstructions(i->second, _location);
+	else
+		return false;
+}
+
+bool AsmAnalyzer::warnOnInstructions(dev::eth::Instruction _instr, SourceLocation const& _location)
 {
 	// We assume that returndatacopy, returndatasize and staticcall are either all available
 	// or all not available.
@@ -725,4 +758,8 @@ void AsmAnalyzer::warnOnInstructions(dev::eth::Instruction _instr, SourceLocatio
 			"Use functions, \"switch\", \"if\" or \"for\" statements instead."
 		);
 	}
+	else
+		return false;
+
+	return true;
 }
diff --git a/libyul/AsmAnalysis.h b/libyul/AsmAnalysis.h
index 0f6eeff35..0a3c08509 100644
--- a/libyul/AsmAnalysis.h
+++ b/libyul/AsmAnalysis.h
@@ -106,7 +106,8 @@ private:
 
 	Scope& scope(Block const* _block);
 	void expectValidType(std::string const& type, langutil::SourceLocation const& _location);
-	void warnOnInstructions(dev::eth::Instruction _instr, langutil::SourceLocation const& _location);
+	bool warnOnInstructions(dev::eth::Instruction _instr, langutil::SourceLocation const& _location);
+	bool warnOnInstructions(std::string const& _instrIdentifier, langutil::SourceLocation const& _location);
 
 	int m_stackHeight = 0;
 	yul::ExternalIdentifierAccess::Resolver m_resolver;
diff --git a/libyul/AsmParser.cpp b/libyul/AsmParser.cpp
index 79bff3f98..0882627cb 100644
--- a/libyul/AsmParser.cpp
+++ b/libyul/AsmParser.cpp
@@ -321,7 +321,12 @@ Parser::ElementaryOperation Parser::parseElementaryOperation()
 		{
 			Identifier identifier{location(), literal};
 			advance();
-			return FunctionCall{identifier.location, identifier, {}};
+			if (m_scanner->currentToken() == Token::LParen)
+				return FunctionCall{identifier.location, identifier, {}};
+			else if (instructions().count(identifier.name.str()))
+				m_errorReporter.syntaxError(identifier.location, "Instructions must be invoked function style. Expecting an '(' after the instruction.");
+			else
+				m_errorReporter.syntaxError(identifier.location, "Invalid identifier.");
 		}
 		else
 			ret = Identifier{location(), literal};