diff --git a/src/sfizz/Region.cpp b/src/sfizz/Region.cpp
index 344d7c6a..d3f635d6 100644
--- a/src/sfizz/Region.cpp
+++ b/src/sfizz/Region.cpp
@@ -208,8 +208,12 @@ bool sfz::Region::parseOpcode(const Opcode& rawOpcode, bool cleanOpcode)
         break;
     // Region logic: key mapping
     case hash("lokey"):
-        triggerOnNote = true;
-        keyRange.setStart(opcode.read(Default::loKey));
+        {
+            absl::optional<uint8_t> optValue = opcode.readOptional(Default::loKey);
+            triggerOnNote = optValue != absl::nullopt;
+            uint8_t value = optValue.value_or(Default::loKey);
+            keyRange.setStart(value);
+        }
         break;
     case hash("hikey"):
         {
diff --git a/tests/RegionValuesT.cpp b/tests/RegionValuesT.cpp
index 633c6afe..a4e3a0f1 100644
--- a/tests/RegionValuesT.cpp
+++ b/tests/RegionValuesT.cpp
@@ -566,17 +566,20 @@ TEST_CASE("[Values] Triggers on note")
         <region> sample=kick.wav hikey=-1
         <region> sample=kick.wav key=-1
         <region> sample=kick.wav hikey=-1 lokey=12
+        <region> sample=kick.wav hikey=-1 lokey=-1
     )");
     synth.dispatchMessage(client, 0, "/region0/trigger_on_note", "", nullptr);
     synth.dispatchMessage(client, 0, "/region1/trigger_on_note", "", nullptr);
     synth.dispatchMessage(client, 0, "/region2/trigger_on_note", "", nullptr);
     // TODO: Double check with Sforzando/rgc
     synth.dispatchMessage(client, 0, "/region3/trigger_on_note", "", nullptr);
+    synth.dispatchMessage(client, 0, "/region4/trigger_on_note", "", nullptr);
     std::vector<std::string> expected {
         "/region0/trigger_on_note,T : {  }",
         "/region1/trigger_on_note,F : {  }",
         "/region2/trigger_on_note,F : {  }",
         "/region3/trigger_on_note,T : {  }",
+        "/region4/trigger_on_note,F : {  }",
     };
     REQUIRE(messageList == expected);
 }