diff --git a/src/com/jpexs/decompiler/flash/gui/FontPanel.java b/src/com/jpexs/decompiler/flash/gui/FontPanel.java
index 8391f62c1..bec8215b4 100644
--- a/src/com/jpexs/decompiler/flash/gui/FontPanel.java
+++ b/src/com/jpexs/decompiler/flash/gui/FontPanel.java
@@ -605,7 +605,9 @@ public class FontPanel extends JPanel {
     }
 
     private void buttonSetAdvanceValuesActionPerformed(ActionEvent evt) {
-        fontTag.setAdvanceValues(((FontFace) fontFaceSelection.getSelectedItem()).font);
+        if (View.showConfirmDialog(null, AppStrings.translate("message.font.setadvancevalues"), AppStrings.translate("message.warning"), JOptionPane.OK_CANCEL_OPTION, JOptionPane.WARNING_MESSAGE, Configuration.showSetAdvanceValuesMessage, JOptionPane.OK_OPTION) == JOptionPane.OK_OPTION) {
+            fontTag.setAdvanceValues(((FontFace) fontFaceSelection.getSelectedItem()).font);
+        }
     }
 
     private void formComponentResized(ComponentEvent evt) {
diff --git a/src/com/jpexs/decompiler/flash/gui/locales/AdvancedSettingsDialog.properties b/src/com/jpexs/decompiler/flash/gui/locales/AdvancedSettingsDialog.properties
index a0d3573ac..aa5af79cd 100644
--- a/src/com/jpexs/decompiler/flash/gui/locales/AdvancedSettingsDialog.properties
+++ b/src/com/jpexs/decompiler/flash/gui/locales/AdvancedSettingsDialog.properties
@@ -436,4 +436,7 @@ config.name.flexSdkLocation = 4) Flex SDK directory path
 config.description.flexSdkLocation = Location of Adobe Flex SDK. It is used mostly for AS3 compilation.
 
 config.name.useFlexAs3Compiler = Use Flex SDK AS3 compiler
-config.description.useFlexAs3Compiler = Use AS3 compiler from Flex SDK while ActionScript direct editation (Flex SDK directory needs to be set)
\ No newline at end of file
+config.description.useFlexAs3Compiler = Use AS3 compiler from Flex SDK while ActionScript direct editation (Flex SDK directory needs to be set)
+
+config.name.showSetAdvanceValuesMessage = Show again information about setting advance values
+config.description.showSetAdvanceValuesMessage = Show again information about setting advance values
diff --git a/src/com/jpexs/decompiler/flash/gui/locales/MainFrame.properties b/src/com/jpexs/decompiler/flash/gui/locales/MainFrame.properties
index 65c5f29d9..5f992623c 100644
--- a/src/com/jpexs/decompiler/flash/gui/locales/MainFrame.properties
+++ b/src/com/jpexs/decompiler/flash/gui/locales/MainFrame.properties
@@ -769,4 +769,6 @@ error.debug.watch.add = Cannot add watch to this variable.
 
 variables.column.scope = Scope
 variables.column.flags = Flags
-variables.column.trait = Trait
\ No newline at end of file
+variables.column.trait = Trait
+
+message.font.setadvancevalues = This operation will set advance of ALL characters in this tag to selected font source advances.
\ No newline at end of file
diff --git a/src/com/jpexs/decompiler/flash/gui/locales/MainFrame_cs.properties b/src/com/jpexs/decompiler/flash/gui/locales/MainFrame_cs.properties
index 26d1b7807..9284a53b8 100644
--- a/src/com/jpexs/decompiler/flash/gui/locales/MainFrame_cs.properties
+++ b/src/com/jpexs/decompiler/flash/gui/locales/MainFrame_cs.properties
@@ -749,4 +749,6 @@ abc.detail.specialmethod.instanceinitializer = Inicializ\u00e1tor instance
 abc.detail.innerfunction = Vnit\u0159n\u00ed funkce
 
 button.edit.script.decompiled = Upravit ActionScript
-button.edit.script.disassembled = Upravit P-k\u00f3d
\ No newline at end of file
+button.edit.script.disassembled = Upravit P-k\u00f3d
+
+message.font.setadvancevalues = Tato operace nastav\u00ed advance V\u0160ECH znak\u016f v tomto tagu na advance hodnoty zdrojov\u00e9ho p\u00edsma.
\ No newline at end of file