diff --git a/tex/chapters/eval.tex b/tex/chapters/eval.tex
index dbf31b6..9eb0502 100644
--- a/tex/chapters/eval.tex
+++ b/tex/chapters/eval.tex
@@ -90,7 +90,7 @@ The target function to optimize the $6$ model parameters for one \docAPshort{} i
 			(s_{i} - \mu_{\mPosVec})^2
 		\enskip,\enskip\enskip
 		\mu_{\mPosVec} = 
-		\mTXP{} + 10 \mPLE{} \log_{10} \| \mPosVec-\mPosAPVec \| + \Delta f \mWAF{} 
+		\mTXP{} - 10 \mPLE{} \log_{10} \| \mPosVec-\mPosAPVec \| + \Delta f \mWAF{} 
 \enspace .
 	\label{eq:optTarget}
 \end{equation}