diff --git a/src/main/resources/data/computercraft/lua/rom/apis/paintutils.lua b/src/main/resources/data/computercraft/lua/rom/apis/paintutils.lua
index b920341c3..f6f1efaac 100644
--- a/src/main/resources/data/computercraft/lua/rom/apis/paintutils.lua
+++ b/src/main/resources/data/computercraft/lua/rom/apis/paintutils.lua
@@ -132,7 +132,17 @@ function drawLine(startX, startY, endX, endY, colour)
         return
     end
 
-    local minX, maxX, minY, maxY = sortCoords(startX, startY, endX, endY)
+    local minX = math.min(startX, endX)
+    local maxX, minY, maxY
+    if minX == startX then
+        minY = startY
+        maxX = endX
+        maxY = endY
+    else
+        minY = endY
+        maxX = startX
+        maxY = startY
+    end
 
     -- TODO: clip to screen rectangle?
 
diff --git a/src/test/resources/test-rom/spec/apis/paintutils_spec.lua b/src/test/resources/test-rom/spec/apis/paintutils_spec.lua
index fc2b6008c..f13bbcfd2 100644
--- a/src/test/resources/test-rom/spec/apis/paintutils_spec.lua
+++ b/src/test/resources/test-rom/spec/apis/paintutils_spec.lua
@@ -67,6 +67,19 @@ describe("The paintutils library", function()
                 { "   ", "000", "ffe" },
             })
         end)
+
+        it("draws a line going diagonally from bottom left", function()
+            local w = with_window(3, 3, function()
+                term.setBackgroundColour(colours.red)
+                paintutils.drawLine(1, 3, 3, 1)
+            end)
+
+            window_eq(w, {
+                { "   ", "000", "ffe" },
+                { "   ", "000", "fef" },
+                { "   ", "000", "eff" },
+            })
+        end)
     end)
 
     describe("paintutils.drawBox", function()