diff --git a/src/PMS/PMS.cpp b/src/PMS/PMS.cpp
index 6bcd8ad..450d128 100644
--- a/src/PMS/PMS.cpp
+++ b/src/PMS/PMS.cpp
@@ -314,11 +314,11 @@ int PMSBase::compensated(int pm25, float humidity) {
   if(pm25 < 30) { /** pm2.5 < 30 */
     value = (fpm25 * 0.524f) - (humidity * 0.0862f) + 5.75f;
   } else if(pm25 < 50) { /** 30 <= pm2.5 < 50 */
-    value = (0.786f * (fpm25 * 0.05f - 1.5f) + 0.524f * (1 - (fpm25 * 0.05f - 1.5f))) * fpm25 - (0.0862f * humidity) + 5.75f;
+    value = (0.786f * (fpm25 * 0.05f - 1.5f) + 0.524f * (1.0f - (fpm25 * 0.05f - 1.5f))) * fpm25 - (0.0862f * humidity) + 5.75f;
   } else if(pm25 < 210) { /** 50 <= pm2.5 < 210 */
     value = (0.786f * fpm25) - (0.0862f * humidity) + 5.75f;
   } else if(pm25 < 260) { /** 210 <= pm2.5 < 260 */
-    value = (0.69f * (fpm25 * 0.02f - 4.2f) + 0.786f * (1 - (fpm25 * 0.02f - 4.2f))) * fpm25 - (0.0862f * humidity * (1 - (fpm25 * 0.02f - 4.2f))) + (2.966f * (fpm25 * 0.02f - 4.2f)) + (5.75f * (1 - (fpm25 * 0.02f - 4.2f))) + (8.84f * (1.e-4) * fpm25 * fpm25 * (fpm25 * 0.02f - 4.2f));
+    value = (0.69f * (fpm25 * 0.02f - 4.2f) + 0.786f * (1.0f - (fpm25 * 0.02f - 4.2f))) * fpm25 - (0.0862f * humidity * (1.0f - (fpm25 * 0.02f - 4.2f))) + (2.966f * (fpm25 * 0.02f - 4.2f)) + (5.75f * (1.0f - (fpm25 * 0.02f - 4.2f))) + (8.84f * (1.e-4) * fpm25 * fpm25 * (fpm25 * 0.02f - 4.2f));
   } else { /** 260 <= pm2.5 */
     value = 2.966f + (0.69f * fpm25) + (8.84f * (1.e-4) * fpm25 * fpm25);
   }