diff --git a/src/test/unit/maths_unittest.cc b/src/test/unit/maths_unittest.cc
index 5082bc6da3..0a20fd63c1 100644
--- a/src/test/unit/maths_unittest.cc
+++ b/src/test/unit/maths_unittest.cc
@@ -70,6 +70,25 @@ TEST(MathsUnittest, TestScaleRangeNegatives)
     EXPECT_EQ(scaleRange(-50, -100, 0, -10, 0), -5);
 }
 
+TEST(MathsUnittest, TestScaleRangeReverse)
+{
+    // Within bounds
+    EXPECT_EQ(scaleRange(0, -10, 0, 0, 100), 100);
+    EXPECT_EQ(scaleRange(-10, -10, 0, 0, 100), 0);
+    EXPECT_EQ(scaleRange(0, -100, 0, 0, 10), 10);
+    EXPECT_EQ(scaleRange(-100, -100, 0, 0, 10), 0);
+
+    // Scale up
+    EXPECT_EQ(scaleRange(-1, -10, 0, 0, 100), 90);
+    EXPECT_EQ(scaleRange(-2, -10, 0, 0, 100), 80);
+    EXPECT_EQ(scaleRange(-5, -10, 0, 0, 100), 50);
+
+    // Scale down
+    EXPECT_EQ(scaleRange(-10, -100, 0, 0, 10), 9);
+    EXPECT_EQ(scaleRange(-20, -100, 0, 0, 10), 8);
+    EXPECT_EQ(scaleRange(-50, -100, 0, 0, 10), 5);
+}
+
 TEST(MathsUnittest, TestConstrain)
 {
     // Within bounds