diff --git a/src/zscanner/Makefile.am b/src/zscanner/Makefile.am
index 35ee513079984eca5bf6d2baff25b1e6d2b8031c..7df4006c6d0d4736298e6a5f9f27fc7c34289370 100644
--- a/src/zscanner/Makefile.am
+++ b/src/zscanner/Makefile.am
@@ -18,10 +18,10 @@ CLEANFILES = descriptor.h descriptor.c
 nodist_libzscanner_la_SOURCES = descriptor.h descriptor.c
 
 descriptor.h: ../common/descriptor.h
-	cp $< $@
+	cp ../common/descriptor.h $@
 
 descriptor.c: ../common/descriptor.c
-	cp $< $@
+	cp ../common/descriptor.c $@
 
 if HAVE_RAGEL
 BUILT_SOURCES += scanner.c