diff --git a/source/code/menudef_themes.cpp b/source/code/menudef_themes.cpp
index a18c666..735b907 100644
--- a/source/code/menudef_themes.cpp
+++ b/source/code/menudef_themes.cpp
@@ -43,11 +43,13 @@ static void testMusic() {
 	highbeatNext = !highbeatNext; //Toggle between standard and highbeat
 }
 
+
+
 class ThemesMenu : public Menu {
-private:
+public:
 	std::shared_ptr<BlockGameSdl> game;
 	sago::SagoTextField themeTitle;
-public:
+
 	ThemesMenu(SDL_Renderer* screen, const std::string& title, bool submenu) : Menu(screen, title, submenu) {
 		game = std::make_shared<BlockGameSdl>(globalData.xsize-450,100,&globalData.spriteHolder->GetDataHolder());
 		game->putSampleBlocks();
@@ -74,12 +76,31 @@ public:
 	}
 };
 
+static int theme2edit = 0;
+
+static void themesEditSlot1() {
+	ThemesMenu tem(globalData.screen, _("Edit custom theme 1"), true);
+	size_t theme_index = ThemeGetNumber("custom_slot_1");
+	if (theme_index == 0) {
+		// Theme not found
+		return;
+	}
+	theme2edit = theme_index;
+	globalData.theme = ThemesGet(theme2edit);
+	RunGameState(tem);
+}
+
+
 void OpenThemesMenu() {
 	ThemesMenu tm(globalData.screen, _("Themes"), true);
 	Button bSwitchTheme;
 	bSwitchTheme.setLabel(_("Switch theme"));
 	bSwitchTheme.setAction(&switchTheme);
 	tm.addButton(&bSwitchTheme);
+	Button bEditTheme1;
+	bEditTheme1.setLabel(_("Edit custom theme 1"));
+	bEditTheme1.setAction(&themesEditSlot1);
+	tm.addButton(&bEditTheme1);
 	if (!globalData.NoSound) {
 		Button bTestMusic;
 		bTestMusic.setLabel(_("Test music"));
diff --git a/source/code/themes.cpp b/source/code/themes.cpp
index be82c95..d9dd7d1 100644
--- a/source/code/themes.cpp
+++ b/source/code/themes.cpp
@@ -35,6 +35,9 @@ https://www.blockattack.net
 using json = nlohmann::json;
 
 
+const int NUMBER_OF_CUSTOM_SLOTS = 2;
+
+
 void to_json(json& j, const ImgScale& p) {
 	switch (p) {
 	case ImgScale::Stretch:
@@ -237,7 +240,7 @@ void ThemesInit() {
 		}
 	}
 	ThemesReadDataFromFile("custom_themes.json");
-	for (int i=1; i <= 4; ++i) {
+	for (int i=1; i <= NUMBER_OF_CUSTOM_SLOTS; ++i) {
 		ThemesAddCustomSlot(themes, i);
 	}
 	ThemesDumpData();
@@ -250,7 +253,18 @@ Theme ThemesGetNext() {
 	return themes.at(current_theme);
 }
 
-Theme ThemesGet(size_t theme_number) {
+Theme& ThemesGet(size_t theme_number) {
 	ThemesInit();
 	return themes.at(theme_number % themes.size());
 }
+
+size_t ThemeGetNumber(const std::string& name) {
+	size_t ret = 0;  // Default to 0
+	ThemesInit();
+	for (size_t i = 0; i < themes.size(); ++i) {
+		if (themes[i].theme_name == name) {
+			ret = i;
+		}
+	}
+	return ret;
+}
diff --git a/source/code/themes.hpp b/source/code/themes.hpp
index 0c471f4..d4a1667 100644
--- a/source/code/themes.hpp
+++ b/source/code/themes.hpp
@@ -70,12 +70,18 @@ Theme ThemesGetNext();
 /**
  * @brief getTheme returns a specific theme
  * @param theme_number
- * @return
+ * @return A reference to the theme. The referance is valid until the next call to a "Themes*" function
  */
-Theme ThemesGet(size_t theme_number);
+Theme& ThemesGet(size_t theme_number);
 
 /**
  * @brief Saves the themes starting with "custom_slot_" to "custom_themes.json"
  *
  */
 void ThemesSaveCustomSlots();
+
+/**
+ * Returns the index of a given file.
+ * Returns 0 if it does not exist or is the standard theme.
+*/
+size_t ThemeGetNumber(const std::string& name);