diff --git a/aegisub/src/ass_override.cpp b/aegisub/src/ass_override.cpp
index e83ccff4f..21d239e13 100644
--- a/aegisub/src/ass_override.cpp
+++ b/aegisub/src/ass_override.cpp
@@ -56,18 +56,13 @@ AssOverrideParameter::AssOverrideParameter()
 {
 }
 
-AssOverrideParameter::AssOverrideParameter(const AssOverrideParameter &param)
-: VariableData(param)
-, classification(param.classification)
-, omitted(param.omitted)
+AssOverrideParameter::AssOverrideParameter(AssOverrideParameter&& o)
+: VariableData(std::move(o))
+, classification(o.classification)
+, omitted(o.omitted)
 {
 }
 
-void AssOverrideParameter::operator=(const AssOverrideParameter &param) {
-	DeleteValue();
-	new(this) AssOverrideParameter(param);
-}
-
 // From ass_dialogue.h
 AssDialogueBlockOverride::~AssDialogueBlockOverride() {
 	delete_clear(Tags);
@@ -117,7 +112,7 @@ void AssDialogueBlockOverride::ProcessParameters(ProcessParametersCallback callb
 	}
 }
 
-AssOverrideParamProto::AssOverrideParamProto(VariableDataType type,int opt,AssParameterClass classi)
+AssOverrideParamProto::AssOverrideParamProto(VariableDataType type, int opt, AssParameterClass classi)
 : optional(opt)
 , type(type)
 , classification(classi)
diff --git a/aegisub/src/ass_override.h b/aegisub/src/ass_override.h
index a739a026a..95e9cdc84 100644
--- a/aegisub/src/ass_override.h
+++ b/aegisub/src/ass_override.h
@@ -68,6 +68,8 @@ enum AssParameterOptional {
 /// A single parameter to an override tag
 class AssOverrideParameter : public VariableData {
 public:
+	AssOverrideParameter(AssOverrideParameter&&);
+
 	/// Type of parameter
 	AssParameterClass classification;
 
@@ -75,8 +77,6 @@ public:
 	bool omitted;
 
 	AssOverrideParameter();
-	AssOverrideParameter(const AssOverrideParameter&);
-	void operator=(const AssOverrideParameter &param);
 };
 
 /// Prototype of a single override parameter
diff --git a/aegisub/src/variable_data.cpp b/aegisub/src/variable_data.cpp
index c1873fb03..da2b35d30 100644
--- a/aegisub/src/variable_data.cpp
+++ b/aegisub/src/variable_data.cpp
@@ -47,6 +47,12 @@ VariableData::VariableData() {
 	value = nullptr;
 }
 
+VariableData::VariableData(VariableData&& o)
+: type(o.type)
+, value(o.value)
+{
+}
+
 VariableData::~VariableData() {
 	DeleteValue();
 }
diff --git a/aegisub/src/variable_data.h b/aegisub/src/variable_data.h
index ec91da2ce..fcbc9d08f 100644
--- a/aegisub/src/variable_data.h
+++ b/aegisub/src/variable_data.h
@@ -34,6 +34,8 @@
 
 #pragma once
 
+#include <boost/noncopyable.hpp>
+
 namespace agi { struct Color; }
 class wxString;
 
@@ -49,7 +51,7 @@ enum VariableDataType {
 
 class AssDialogueBlockOverride;
 
-class VariableData {
+class VariableData : private boost::noncopyable {
 private:
 	union {
 		void *value;
@@ -68,6 +70,7 @@ protected:
 
 public:
 	VariableData();
+	VariableData(VariableData&& o);
 	virtual ~VariableData();
 
 	VariableDataType GetType() const { return type; }