diff --git a/Makefile.am b/Makefile.am
index 346879c..470ccab 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -135,7 +135,7 @@ BUILT_SOURCES += frontends/LexRain.hs
 # For dummy modules:
 modules_DATA = 
 # For dummy lib files:
-tockinc_DATA = occamutl.tock.inc occamutl.tock.h occamutl.tock.sizes
+tockinc_DATA = occamutl.lib.tock.inc occamutl.lib.tock.h occamutl.lib.tock.sizes
 
 CLEANFILES = $(BUILT_SOURCES) $(config_sources)
 
diff --git a/occamutl.tock.h b/occamutl.lib.tock.h
similarity index 100%
rename from occamutl.tock.h
rename to occamutl.lib.tock.h
diff --git a/occamutl.tock.inc b/occamutl.lib.tock.inc
similarity index 100%
rename from occamutl.tock.inc
rename to occamutl.lib.tock.inc
diff --git a/occamutl.tock.sizes b/occamutl.lib.tock.sizes
similarity index 100%
rename from occamutl.tock.sizes
rename to occamutl.lib.tock.sizes