diff --git a/makefile b/makefile
index 901a3ef2..70316a4a 100644
--- a/makefile
+++ b/makefile
@@ -329,19 +329,19 @@ profile:
 #This rule cleans the source tree of all compiled code, not including the pdf
 #documentation.
 clean:
-	rm -f `find . -type f | grep "[.]o" | xargs`
-	rm -f `find . -type f | grep "[.]lo"  | xargs`
-	rm -f `find . -type f | grep "[.]a" | xargs`
-	rm -f `find . -type f | grep "[.]la"  | xargs`
-	rm -f `find . -type f | grep "[.]obj" | xargs`
-	rm -f `find . -type f | grep "[.]lib" | xargs`
-	rm -f `find . -type f | grep "[.]exe" | xargs`
-	rm -f `find . -type f | grep "[.]gcda" | xargs`
-	rm -f `find . -type f | grep "[.]gcno" | xargs`
-	rm -f `find . -type f | grep "[.]il" | xargs`
-	rm -f `find . -type f | grep "[.]dyn" | xargs`
-	rm -f `find . -type f | grep "[.]dpi" | xargs`
-	rm -rf `find . -type d | grep "[.]libs" | xargs`
+	rm -f `find . -type f -name "*.o" | xargs`
+	rm -f `find . -type f -name "*.lo"  | xargs`
+	rm -f `find . -type f -name "*.a" | xargs`
+	rm -f `find . -type f -name "*.la"  | xargs`
+	rm -f `find . -type f -name "*.obj" | xargs`
+	rm -f `find . -type f -name "*.lib" | xargs`
+	rm -f `find . -type f -name "*.exe" | xargs`
+	rm -f `find . -type f -name "*.gcda" | xargs`
+	rm -f `find . -type f -name "*.gcno" | xargs`
+	rm -f `find . -type f -name "*.il" | xargs`
+	rm -f `find . -type f -name "*.dyn" | xargs`
+	rm -f `find . -type f -name "*.dpi" | xargs`
+	rm -rf `find . -type d -name "*.libs" | xargs`
 	rm -f crypt.aux  crypt.dvi  crypt.idx  crypt.ilg  crypt.ind  crypt.log crypt.toc
 	rm -f $(TV) $(PROF) $(SMALL) $(CRYPT) $(HASHSUM) $(MULTI) $(TIMING) $(TEST)
 	rm -rf doc/doxygen