diff --git a/tools/yulPhaser/Population.cpp b/tools/yulPhaser/Population.cpp
index 169cbfe30..b336daf73 100644
--- a/tools/yulPhaser/Population.cpp
+++ b/tools/yulPhaser/Population.cpp
@@ -117,15 +117,21 @@ Population Population::crossover(PairSelection const& _selection, function<Cross
 	return Population(m_fitnessMetric, crossedIndividuals);
 }
 
+namespace solidity::phaser
+{
+
 Population operator+(Population _a, Population _b)
 {
 	// This operator is meant to be used only with populations sharing the same metric (and, to make
 	// things simple, "the same" here means the same exact object in memory).
 	assert(_a.m_fitnessMetric == _b.m_fitnessMetric);
 
+	using ::operator+; // Import the std::vector concat operator from CommonData.h
 	return Population(_a.m_fitnessMetric, move(_a.m_individuals) + move(_b.m_individuals));
 }
 
+}
+
 bool Population::operator==(Population const& _other) const
 {
 	// We consider populations identical only if they share the same exact instance of the metric.
diff --git a/tools/yulPhaser/Population.h b/tools/yulPhaser/Population.h
index f8f12632e..40d51498b 100644
--- a/tools/yulPhaser/Population.h
+++ b/tools/yulPhaser/Population.h
@@ -29,17 +29,6 @@
 namespace solidity::phaser
 {
 
-class Population;
-
-}
-
-// This operator+ must be declared in the global namespace. Otherwise it would shadow global
-// operator+ overloads from CommonData.h (e.g. the one for vector) in the namespace it was declared in.
-solidity::phaser::Population operator+(solidity::phaser::Population _a, solidity::phaser::Population _b);
-
-namespace solidity::phaser
-{
-
 class PairSelection;
 class Selection;
 
@@ -108,7 +97,8 @@ public:
 	Population select(Selection const& _selection) const;
 	Population mutate(Selection const& _selection, std::function<Mutation> _mutation) const;
 	Population crossover(PairSelection const& _selection, std::function<Crossover> _crossover) const;
-	friend Population (::operator+)(Population _a, Population _b);
+
+	friend Population operator+(Population _a, Population _b);
 
 	std::shared_ptr<FitnessMetric> fitnessMetric() { return m_fitnessMetric; }
 	std::vector<Individual> const& individuals() const { return m_individuals; }