diff --git a/Tracking/TrkFitter/TrkGaussianSumFilter/TrkGaussianSumFilter/KLGaussianMixtureReduction.h b/Tracking/TrkFitter/TrkGaussianSumFilter/TrkGaussianSumFilter/KLGaussianMixtureReduction.h
index 271523439a5670c8edd3dbb857df0e884c34913b..21d9d1935d379f7060c8a75e274c6e2bcce2a08a 100644
--- a/Tracking/TrkFitter/TrkGaussianSumFilter/TrkGaussianSumFilter/KLGaussianMixtureReduction.h
+++ b/Tracking/TrkFitter/TrkGaussianSumFilter/TrkGaussianSumFilter/KLGaussianMixtureReduction.h
@@ -110,7 +110,7 @@ struct triangularToIJ
  * @brief Merge the componentsIn and return
  * which componets got merged
  *
- * The inpupt component array is assumed to be
+ * The input component array is assumed to be
  * GSFUtils::alignment aligned.
  *
  */