diff --git a/mk/config.mk.in b/mk/config.mk.in
index 35ce354849598efb2bcb0eb9ad6d6ec571300660..83b6fb190a6193c4d9be536304a84a932715aa7a 100644
--- a/mk/config.mk.in
+++ b/mk/config.mk.in
@@ -468,6 +468,14 @@ CTAGS 			= $(ETAGS)
 RAWCPP                  = @RAWCPP@
 GNUCPP                  = @GNUCPP@
 INSTALL			= @INSTALL@
+#
+# Sigh - the autoconf macro for INSTALL will subst a relative path to the fallback
+# install-sh script (if chosen). This not terribly useful to us, so we convert
+# it into an abs. path.
+# 
+if "$(INSTALL)" ".././install-sh"
+INSTALL			= $(FPTOOLS_TOP_ABS)/install-sh
+endif
 LATEX			= latex
 LN_S			= @LN_S@
 MANMACROS		= -man