diff --git a/src/sfizz/ModifierHelpers.h b/src/sfizz/ModifierHelpers.h
index 5ea57c02..609b16ff 100644
--- a/src/sfizz/ModifierHelpers.h
+++ b/src/sfizz/ModifierHelpers.h
@@ -271,8 +271,8 @@ void pitchBendEnvelope(const EventVector& events, absl::Span<float> envelope, F&
 template <class F>
 void linearModifier(const sfz::Resources& resources, absl::Span<float> span, const sfz::CCData<sfz::Modifier>& ccData, F&& lambda)
 {
-    const auto events = resources.midiState.getCCEvents(ccData.cc);
-    const auto curve = resources.curves.getCurve(ccData.data.curve);
+    const auto& events = resources.midiState.getCCEvents(ccData.cc);
+    const auto& curve = resources.curves.getCurve(ccData.data.curve);
     if (ccData.data.step == 0.0f) {
         linearEnvelope(events, span, [&ccData, &curve, &lambda](float x) {
             return lambda(curve.evalNormalized(x) * ccData.data.value);
@@ -301,8 +301,8 @@ void linearModifier(const sfz::Resources& resources, absl::Span<float> span, con
 template <class F>
 void multiplicativeModifier(const sfz::Resources& resources, absl::Span<float> span, const sfz::CCData<sfz::Modifier>& ccData, F&& lambda)
 {
-    const auto events = resources.midiState.getCCEvents(ccData.cc);
-    const auto curve = resources.curves.getCurve(ccData.data.curve);
+    const auto& events = resources.midiState.getCCEvents(ccData.cc);
+    const auto& curve = resources.curves.getCurve(ccData.data.curve);
     if (ccData.data.step == 0.0f) {
         multiplicativeEnvelope(events, span, [&ccData, &curve, &lambda](float x) {
             return lambda(curve.evalNormalized(x) * ccData.data.value);
diff --git a/src/sfizz/Voice.cpp b/src/sfizz/Voice.cpp
index 6dff257b..771900d1 100644
--- a/src/sfizz/Voice.cpp
+++ b/src/sfizz/Voice.cpp
@@ -142,7 +142,7 @@ void sfz::Voice::startVoice(Region* region, int delay, int number, float value,
         ASSERT(modifierSmoothers[modId].size() >= region->modifiers[modId].size());
         forEachWithSmoother(modId, [modId, this](const CCData<Modifier>& mod, Smoother& smoother) {
             const auto ccValue = resources.midiState.getCCValue(mod.cc);
-            const auto curve = resources.curves.getCurve(mod.data.curve);
+            const auto& curve = resources.curves.getCurve(mod.data.curve);
             const auto finalValue = curve.evalNormalized(ccValue) * mod.data.value;
             switch (modId) {
             case Mod::volume:
@@ -347,7 +347,7 @@ void sfz::Voice::applyCrossfades(absl::Span<float> modulationSpan) noexcept
 
     bool canShortcut = true;
     for (const auto& mod : region->crossfadeCCInRange) {
-        const auto events = resources.midiState.getCCEvents(mod.cc);
+        const auto& events = resources.midiState.getCCEvents(mod.cc);
         canShortcut &= (events.size() == 1);
         linearEnvelope(events, *tempSpan, [&](float x) {
             return crossfadeIn(mod.data, x, xfCurve);
@@ -356,7 +356,7 @@ void sfz::Voice::applyCrossfades(absl::Span<float> modulationSpan) noexcept
     }
 
     for (const auto& mod : region->crossfadeCCOutRange) {
-        const auto events = resources.midiState.getCCEvents(mod.cc);
+        const auto& events = resources.midiState.getCCEvents(mod.cc);
         canShortcut &= (events.size() == 1);
         linearEnvelope(events, *tempSpan, [&](float x) {
             return crossfadeOut(mod.data, x, xfCurve);