diff --git a/.gitignore b/.gitignore
index 5a035eb4c..c3669d44c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -52,6 +52,8 @@ src/test-recorder
 src/test-recorder.ogg
 src/test-theme
 src/st.h
+src/stamp-st.h
+src/stamp-st.h.tmp
 stamp-h1
 tests/run-test.sh
 xmldocs.make
diff --git a/src/Makefile-st.am b/src/Makefile-st.am
index 4d5d5476e..579223526 100644
--- a/src/Makefile-st.am
+++ b/src/Makefile-st.am
@@ -100,11 +100,16 @@ st_source_h =					\
 	st/st-widget.h				\
 	$(NULL)
 
-st.h: Makefile
+st.h: stamp-st.h
+	@true
+stamp-st.h: Makefile
 	$(AM_V_GEN) (echo "#define ST_H_INSIDE 1";	\
 	for name in $(st_source_h); do			\
 	  echo "#include <"$$name">";			\
-	done; echo "#undef ST_H_INSIDE") > st.h.tmp && mv st.h.tmp st.h
+	done; echo "#undef ST_H_INSIDE") > $@.tmp &&  \
+	(cmp -s $@.tmp st.h || cp $@.tmp st.h) &&	\
+	rm -f $@.tmp &&				\
+	echo timestamp > $(@F)
 
 BUILT_SOURCES += st.h