diff --git a/include/engine/Module.hpp b/include/engine/Module.hpp
index 6f6107e9..966e3f13 100644
--- a/include/engine/Module.hpp
+++ b/include/engine/Module.hpp
@@ -309,7 +309,7 @@ struct Module {
 		return rightExpander;
 	}
 	/** Returns the left Expander for `side = 0` and the right Expander for `side = 1`. */
-	Expander& getExpander(int side) {
+	Expander& getExpander(uint8_t side) {
 		return side ? rightExpander : leftExpander;
 	}
 
@@ -420,8 +420,8 @@ struct Module {
 	}
 
 	struct ExpanderChangeEvent {
-		/** False for left, true for right. */
-		bool side;
+		/** 0 for left, 1 for right. */
+		uint8_t side;
 	};
 	/** Called after an expander is added, removed, or changed on either the left or right side of the Module.
 	*/
diff --git a/src/engine/Engine.cpp b/src/engine/Engine.cpp
index 277b01a1..89566bd2 100644
--- a/src/engine/Engine.cpp
+++ b/src/engine/Engine.cpp
@@ -244,7 +244,7 @@ struct Engine::Internal {
 };
 
 
-static void Engine_updateExpander_NoLock(Engine* that, Module* module, bool side) {
+static void Engine_updateExpander_NoLock(Engine* that, Module* module, uint8_t side) {
 	Module::Expander& expander = side ? module->rightExpander : module->leftExpander;
 	Module* oldExpanderModule = expander.module;