diff --git a/aegisub/src/ass_dialogue.cpp b/aegisub/src/ass_dialogue.cpp
index 418724962..2cf9cff17 100644
--- a/aegisub/src/ass_dialogue.cpp
+++ b/aegisub/src/ass_dialogue.cpp
@@ -269,11 +269,6 @@ void AssDialogue::UpdateText(boost::ptr_vector<AssDialogueBlock>& blocks) {
 	Text = join(blocks | transformed(get_text), "");
 }
 
-void AssDialogue::SetMarginString(std::string const& origvalue, int which) {
-	if (which < 0 || which > 2) throw InvalidMarginIdError();
-	Margin[which] = mid<int>(0, atoi(origvalue.c_str()), 9999);
-}
-
 std::string AssDialogue::GetMarginString(int which) const {
 	if (which < 0 || which > 2) throw InvalidMarginIdError();
 	return std::to_string(Margin[which]);
diff --git a/aegisub/src/ass_dialogue.h b/aegisub/src/ass_dialogue.h
index 8da137a12..24fd11b38 100644
--- a/aegisub/src/ass_dialogue.h
+++ b/aegisub/src/ass_dialogue.h
@@ -169,12 +169,6 @@ public:
 	void UpdateText(boost::ptr_vector<AssDialogueBlock>& blocks);
 	const std::string GetEntryData() const override;
 
-	template<int which>
-	void SetMarginString(std::string const& value) { SetMarginString(value, which);}
-	/// @brief Set a margin
-	/// @param value New value of the margin
-	/// @param which 0 = left, 1 = right, 2 = vertical
-	void SetMarginString(std::string const& value, int which);
 	/// @brief Get a margin
 	/// @param which 0 = left, 1 = right, 2 = vertical
 	std::string GetMarginString(int which) const;