diff --git a/src/Makefile.am b/src/Makefile.am
index 46010a7ace993dce98a84add41d30bdab34ccb06..ed547937333e5231af06d85336e57c60587c06e0 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -105,7 +105,7 @@ DISTCHECK_CONFIGURE_FLAGS = \
 include $(top_srcdir)/am/global-rules
 
 BUILT_SOURCES = timestepping.hh timestepping.cc
-$(srcdir)/timestepping.cc: $(srcdir)/timestepping.org
+$(srcdir)/timestepping.cc $(srcdir)/timestepping.hh: $(srcdir)/timestepping.org
 	emacs -Q --batch --eval \
 	  "(let (vc-handled-backends) \
 	      (org-babel-tangle-file \"$<\" nil 'c++))"