diff --git a/ChangeLog.txt b/ChangeLog.txt
index ef5f412c0..98185333d 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -10,6 +10,7 @@
 - [#689] Grainline default values swapped around.
 - [#688] Difficult to enter numbers in Tape.
 - Fixed bug in Tape app. Tape showed birth date in wrong locale.
+- Fixed bug in dialog Internal Piece Path. Value from the field After rewrited data in the field Before. 
 
 # Version 0.5.0 May 9, 2017
 - [#581] User can now filter input lists by keyword in function wizard.
diff --git a/src/libs/vtools/dialogs/tools/dialogpiecepath.cpp b/src/libs/vtools/dialogs/tools/dialogpiecepath.cpp
index 5911971fd..8f8b0938e 100644
--- a/src/libs/vtools/dialogs/tools/dialogpiecepath.cpp
+++ b/src/libs/vtools/dialogs/tools/dialogpiecepath.cpp
@@ -575,16 +575,17 @@ void DialogPiecePath::EvalWidthBefore()
 {
     labelEditFormula = ui->labelEditBefore;
     const QString postfix = VDomDocument::UnitsToStr(qApp->patternUnit(), true);
-    const QString formula = ui->plainTextEditFormulaWidthBefore->toPlainText();
+    QString formula = ui->plainTextEditFormulaWidthBefore->toPlainText();
     bool flagFormula = false; // fake flag
     Eval(formula, flagFormula, ui->labelResultBefore, postfix, false, true);
 
+    formula = GetFormulaSAWidthBefore();
     if (formula != currentSeamAllowance)
     {
         ui->pushButtonDefBefore->setEnabled(true);
     }
 
-    UpdateNodeSABefore(GetFormulaSAWidthBefore());
+    UpdateNodeSABefore(formula);
 }
 
 //---------------------------------------------------------------------------------------------------------------------
@@ -592,16 +593,17 @@ void DialogPiecePath::EvalWidthAfter()
 {
     labelEditFormula = ui->labelEditAfter;
     const QString postfix = VDomDocument::UnitsToStr(qApp->patternUnit(), true);
-    const QString formula = ui->plainTextEditFormulaWidthAfter->toPlainText();
+    QString formula = ui->plainTextEditFormulaWidthAfter->toPlainText();
     bool flagFormula = false; // fake flag
     Eval(formula, flagFormula, ui->labelResultAfter, postfix, false, true);
 
+    formula = GetFormulaSAWidthAfter();
     if (formula != currentSeamAllowance)
     {
         ui->pushButtonDefAfter->setEnabled(true);
     }
 
-    UpdateNodeSABefore(GetFormulaSAWidthAfter());
+    UpdateNodeSAAfter(formula);
 }
 
 //---------------------------------------------------------------------------------------------------------------------