diff --git a/extern/libtommath/makefile b/extern/libtommath/makefile
index 25effac2fa..20f179ff7c 100644
--- a/extern/libtommath/makefile
+++ b/extern/libtommath/makefile
@@ -166,7 +166,7 @@ pretty:
 
 clean:
 	rm -f *.bat *.pdf *.o *.a *.obj *.lib *.exe *.dll etclib/*.o demo/demo.o test ltmtest mpitest mtest/mtest mtest/mtest.exe \
-        *.idx *.toc *.log *.aux *.dvi *.lof *.ind *.ilg *.ps *.log *.s mpi.c *.da *.dyn *.dpi tommath.tex `find . -type f | grep [~] | xargs` *.lo *.la
+        *.idx *.toc *.log *.aux *.dvi *.lof *.ind *.ilg *.ps *.log *.s mpi.c *.da *.dyn *.dpi tommath.tex `find . -type f | grep [~] | xargs` *.lo *.la *.d
 	rm -rf .libs
 
 #zipup the project (take that!)