diff --git a/tests/test_sensorcommands.cpp b/tests/test_sensorcommands.cpp
index a0ca740..5513603 100644
--- a/tests/test_sensorcommands.cpp
+++ b/tests/test_sensorcommands.cpp
@@ -52,6 +52,12 @@
         EXPECT_EQ(bExp, 0);
     }
 
+    // check negative values
+    expected = 236; // 2s compliment -20
+    scaledVal = ipmi::scaleIPMIValueFromDouble(-20, mValue, rExp, bValue, bExp,
+                                               bSigned);
+    EXPECT_NEAR(scaledVal, expected, expected * 0.01);
+
     // fan example
     maxValue = 16000;
     minValue = 0;