diff --git a/lib/asn1/Makefile.am b/lib/asn1/Makefile.am
index 3617e4eea..75cd974e4 100644
--- a/lib/asn1/Makefile.am
+++ b/lib/asn1/Makefile.am
@@ -6,7 +6,7 @@ lib_LIBRARIES = libasn1.a
 
 SUFFIXES = .x
 
-gen_SOURCES = asn1_Realm.c asn1_PrincipalName.c \
+BUILT_SOURCES = asn1_Realm.c asn1_PrincipalName.c \
 	asn1_HostAddress.c asn1_HostAddresses.c asn1_KerberosTime.c \
 	asn1_AuthorizationData.c asn1_APOptions.c asn1_TicketFlags.c \
 	asn1_KDCOptions.c asn1_LastReq.c asn1_EncryptedData.c \
@@ -20,12 +20,12 @@ gen_SOURCES = asn1_Realm.c asn1_PrincipalName.c \
 	asn1_KRB_PRIV.c asn1_EncKrbPrivPart.c asn1_KRB_CRED.c \
 	asn1_KrbCredInfo.c asn1_EncKrbCredPart.c asn1_KRB_ERROR.c
 
-foo=$(gen_SOURCES:%.c=%.x)
+foo=$(BUILT_SOURCES:%.c=%.x)
 
 
 libasn1_a_SOURCES = der_get.c der_put.c der_free.c der_length.c der_copy.c \
 		timegm.c \
-		$(gen_SOURCES)
+		$(BUILT_SOURCES)
 
 noinst_PROGRAMS = asn1_compile
 
@@ -35,7 +35,7 @@ asn1_compile_SOURCES = parse.y lex.l main.c hash.c symbol.c gen.c \
 
 asn1_compile_LDADD = @LEXLIB@
 
-CLEANFILES = lex.c parse.c parse.h asn1.h $(gen_SOURCES) $(foo) asn1_files
+CLEANFILES = lex.c parse.c parse.h asn1.h $(BUILT_SOURCES) $(foo) asn1_files
 
 parse.c: parse.y
 	$(YACC) -d $(YFLAGS) $(srcdir)/parse.y
@@ -57,8 +57,10 @@ lex.o: parse.h
 #	$(AR) cru libasn1.a $(libasn1_a_OBJECTS) $(libasn1_a_LIBADD) $$o && \
 #	$(RANLIB) libasn1.a
 
-$(foo): asn1_compile $(srcdir)/k5.asn1
+$(foo) asn1.h: asn1_compile $(srcdir)/k5.asn1
 	./asn1_compile $(srcdir)/k5.asn1
 
-%.c: %.x
+$(libasn1_a_SOURCES): asn1.h
+
+.x.c:
 	@cmp -s $< $@ 2> /dev/null || cp $< $@