diff --git a/src/Timesheet/RateService.php b/src/Timesheet/RateService.php
index 96e23179ab..9137260e0f 100644
--- a/src/Timesheet/RateService.php
+++ b/src/Timesheet/RateService.php
@@ -85,7 +85,11 @@ public function calculate(Timesheet $record): Rate
             }
         }
 
-        $factor = $this->getRateFactor($record);
+        $factor = 1.00;
+        // do not apply once a value was calculated - see https://github.com/kevinpapst/kimai2/issues/1988
+        if ($record->getFixedRate() === null && $record->getHourlyRate() === null) {
+            $factor = $this->getRateFactor($record);
+        }
 
         $factoredHourlyRate = (float) ($hourlyRate * $factor);
         $factoredInternalRate = (float) ($internalRate * $factor);