diff --git a/libyul/CMakeLists.txt b/libyul/CMakeLists.txt
index 18a96049d..59fb6d468 100644
--- a/libyul/CMakeLists.txt
+++ b/libyul/CMakeLists.txt
@@ -129,6 +129,8 @@ add_library(yul
 	optimiser/FullInliner.h
 	optimiser/FunctionCallFinder.cpp
 	optimiser/FunctionCallFinder.h
+	optimiser/FunctionDefinitionCollector.cpp
+	optimiser/FunctionDefinitionCollector.h
 	optimiser/FunctionGrouper.cpp
 	optimiser/FunctionGrouper.h
 	optimiser/FunctionHoister.cpp
diff --git a/libyul/optimiser/FunctionDefinitionCollector.cpp b/libyul/optimiser/FunctionDefinitionCollector.cpp
new file mode 100644
index 000000000..70f2a268d
--- /dev/null
+++ b/libyul/optimiser/FunctionDefinitionCollector.cpp
@@ -0,0 +1,36 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <libyul/optimiser/FunctionDefinitionCollector.h>
+#include <libyul/AST.h>
+
+using namespace std;
+using namespace solidity;
+using namespace solidity::yul;
+
+map<YulString, FunctionDefinition const*> FunctionDefinitionCollector::run(Block& _block)
+{
+	FunctionDefinitionCollector functionDefinitionCollector;
+	functionDefinitionCollector(_block);
+	return functionDefinitionCollector.m_functionDefinitions;
+}
+
+void FunctionDefinitionCollector::operator()(FunctionDefinition const& _functionDefinition)
+{
+	m_functionDefinitions[_functionDefinition.name] = &_functionDefinition;
+	ASTWalker::operator()(_functionDefinition);
+}
diff --git a/libyul/optimiser/FunctionDefinitionCollector.h b/libyul/optimiser/FunctionDefinitionCollector.h
new file mode 100644
index 000000000..c97f20d67
--- /dev/null
+++ b/libyul/optimiser/FunctionDefinitionCollector.h
@@ -0,0 +1,44 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * AST walker that finds all function definitions and stores them into a map indexed by the function names.
+ */
+#pragma once
+
+#include <libyul/optimiser/ASTWalker.h>
+
+#include <map>
+
+namespace solidity::yul
+{
+
+/**
+ * AST walker that finds all function definitions and stores them into a map indexed by the function names.
+ *
+ * Prerequisite: Disambiguator
+ */
+class FunctionDefinitionCollector: ASTWalker
+{
+public:
+	static std::map<YulString, FunctionDefinition const*> run(Block& _block);
+private:
+	using ASTWalker::operator();
+	void operator()(FunctionDefinition const& _functionDefinition) override;
+	std::map<YulString, FunctionDefinition const*> m_functionDefinitions;
+};
+
+}