diff --git a/CMakeLists.txt b/CMakeLists.txt
index cc1db3e..dc07310 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -316,7 +316,10 @@ if ("${CMAKE_BUILD_TYPE}" STREQUAL "Release" AND "${STATIC_BUILD}")
     set (CPACK_NSIS_INSTALLED_ICON_NAME "bin\\\\planetblupi.exe")
     set (CPACK_NSIS_URL_INFO_ABOUT "http://www.blupi.org")
     set (CPACK_NSIS_MUI_FINISHPAGE_RUN "planetblupi")
-    set (CPACK_NSIS_SIGN_UNINSTALLER "sign -a -fd sha1 -t http://time.certum.pl -v")
+    if (SIGN_APP
+      set (CPACK_NSIS_SIGN_UNINSTALLER "sign -a -fd sha1 -t http://time.certum.pl -v")
+    endif ()
+
     include (CPack)
 
     find_program (SIGNTOOL_EXECUTABLE signtool)