diff --git a/native/src/defines.h b/native/src/defines.h
index 2121534..e882c37 100644
--- a/native/src/defines.h
+++ b/native/src/defines.h
@@ -171,7 +171,7 @@
 #define EQUIVALENT_CHAR_WITHOUT_DISTANCE_INFO -2
 #define PROXIMITY_CHAR_WITHOUT_DISTANCE_INFO -3
 #define ADDITIONAL_PROXIMITY_CHAR_DISTANCE_INFO -4
-#define NOT_A_INDEX -1
+#define NOT_AN_INDEX -1
 #define NOT_A_FREQUENCY -1
 
 #define KEYCODE_SPACE ' '
diff --git a/native/src/proximity_info.cpp b/native/src/proximity_info.cpp
index 47f1376..2bfb15d 100644
--- a/native/src/proximity_info.cpp
+++ b/native/src/proximity_info.cpp
@@ -304,7 +304,7 @@
 
 float ProximityInfo::calculateNormalizedSquaredDistance(
         const int keyIndex, const int inputIndex) const {
-    if (keyIndex == NOT_A_INDEX) {
+    if (keyIndex == NOT_AN_INDEX) {
         return NOT_A_DISTANCE_FLOAT;
     }
     if (!hasSweetSpotData(keyIndex)) {
@@ -325,11 +325,11 @@
 int ProximityInfo::getKeyIndex(const int c) const {
     if (KEY_COUNT == 0) {
         // We do not have the coordinate data
-        return NOT_A_INDEX;
+        return NOT_AN_INDEX;
     }
     const unsigned short baseLowerC = toBaseLowerCase(c);
     if (baseLowerC > MAX_CHAR_CODE) {
-        return NOT_A_INDEX;
+        return NOT_AN_INDEX;
     }
     return mCodeToKeyIndex[baseLowerC];
 }