diff --git a/win/pw3270.nsi.in b/win/pw3270.nsi.in
index 550872a..f1170b5 100644
--- a/win/pw3270.nsi.in
+++ b/win/pw3270.nsi.in
@@ -292,6 +292,9 @@ Section "Uninstall"
 	# Always delete uninstaller first
 	delete $INSTDIR\uninstaller.exe
 
+	# Remove association
+	${UnRegisterExtension} ".3270" "@PRODUCT_NAME@ Session file"
+
 	# Set SMPROGRAMS and DESKTOP path
 	SetShellVarContext all
 
--
libgit2 0.21.2