diff --git a/app/src/main/java/gui/SudokuRenderer.java b/app/src/main/java/gui/SudokuRenderer.java
index 604d38d..da2916b 100644
--- a/app/src/main/java/gui/SudokuRenderer.java
+++ b/app/src/main/java/gui/SudokuRenderer.java
@@ -96,7 +96,7 @@ public class SudokuRenderer {
 					String cellText = "";
 					if (symbol != -1)
 						cellText += Integer.toString(symbol + 1);
-					if (ImGui.button(cellText + "##" + index, cellSize)) {
+					if (ImGui.button(cellText + "##" + index, cellSize) && cell.isMutable()) {
 						ImGui.openPopup("editPopup");
 						currentCell = cell;
 					}