diff --git a/src/MAX30105.cpp b/src/MAX30105.cpp
index 742c313..230a66f 100644
--- a/src/MAX30105.cpp
+++ b/src/MAX30105.cpp
@@ -162,7 +162,7 @@ boolean MAX30105::begin(TwoWire &wirePort, uint32_t i2cSpeed, uint8_t i2caddr) {
 
   // Step 1: Initial Communication and Verification
   // Check that a MAX30105 is connected
-  if (!readPartID() == MAX_30105_EXPECTEDPARTID) {
+  if (readPartID() != MAX_30105_EXPECTEDPARTID) {
     // Error -- Part ID read from MAX30105 does not match expected part ID.
     // This may mean there is a physical connectivity problem (broken wire, unpowered, etc).
     return false;