diff --git a/crypto/srp/Makefile b/crypto/srp/Makefile
index d37d46c260..81b4197758 100644
--- a/crypto/srp/Makefile
+++ b/crypto/srp/Makefile
@@ -42,7 +42,8 @@ links:
 	@$(PERL) $(TOP)/util/mklink.pl ../../apps $(APPS)
 
 install:
-	@for i in $(EXHEADER) ; \
+	@[ -n "$(INSTALLTOP)" ] # should be set by top Makefile...
+	@headerlist="$(EXHEADER)"; for i in $$headerlist ; \
 	do  \
 	(cp $$i $(INSTALL_PREFIX)$(INSTALLTOP)/include/openssl/$$i; \
 	chmod 644 $(INSTALL_PREFIX)$(INSTALLTOP)/include/openssl/$$i ); \