diff --git a/cmake/modules/KatieBuildMacros.cmake b/cmake/modules/KatieBuildMacros.cmake
index f8f07f653..7948245d1 100644
--- a/cmake/modules/KatieBuildMacros.cmake
+++ b/cmake/modules/KatieBuildMacros.cmake
@@ -206,10 +206,10 @@ function(KATIE_SETUP_TARGET FORTARGET)
         foreach(srcstring ${ARGN})
             get_filename_component(srcext ${srcstring} EXT)
             get_source_file_property(skip ${srcstring} ALLINONE_EXCLUDE)
-            if(skip)
+            if(skip OR "${srcext}" STREQUAL ".c")
                 katie_warning("Source is excluded: ${srcstring}")
-                set(srcstring ${srcstring} ${srcstring})
-            elseif(NOT "${srcext}" MATCHES "(.h|.qrc|.ui)" AND NOT "${srcext}" STREQUAL ".c")
+                set(excludesources ${excludesources} ${srcstring})
+            elseif(NOT "${srcext}" MATCHES "(.h|.qrc|.ui)")
                 set(allinonedata "${allinonedata}#include \"${srcstring}\"\n")
             endif()
         endforeach()