diff --git a/autotests/CMakeLists.txt b/autotests/CMakeLists.txt
index 098af33d9..82b44fa05 100644
--- a/autotests/CMakeLists.txt
+++ b/autotests/CMakeLists.txt
@@ -53,7 +53,7 @@ if(Poppler_Qt5_FOUND)
         LINK_LIBRARIES Qt5::Widgets Qt5::Test okularcore
     )
 
-    ecm_add_test(signunsignedfieldtest
+    ecm_add_test(signunsignedfieldtest.cpp
         TEST_NAME "signunsignedfieldtest"
         LINK_LIBRARIES Qt5::Widgets Qt5::Test okularcore
     )