diff --git a/src/pl/plperl/GNUmakefile b/src/pl/plperl/GNUmakefile
index cabe9a92e292c73bed3d2363d61f442ff95c8e9c..a0bb140034a9e1d9f4c2b73dad160b661d7cfbb8 100644
--- a/src/pl/plperl/GNUmakefile
+++ b/src/pl/plperl/GNUmakefile
@@ -1,5 +1,5 @@
 # Makefile for PL/Perl
-# $PostgreSQL: pgsql/src/pl/plperl/GNUmakefile,v 1.35 2008/10/01 22:38:56 petere Exp $
+# $PostgreSQL: pgsql/src/pl/plperl/GNUmakefile,v 1.36 2008/10/02 08:11:11 petere Exp $
 
 subdir = src/pl/plperl
 top_builddir = ../../..
@@ -57,7 +57,7 @@ installdirs: installdirs-lib
 uninstall: uninstall-lib
 
 installcheck: submake
-	$(top_builddir)/src/test/regress/pg_regress --psqldir=$(PSQLDIR) $(REGRESS_OPTS) $(REGRESS)
+	$(top_builddir)/src/test/regress/pg_regress --inputdir=$(srcdir) --psqldir=$(PSQLDIR) $(REGRESS_OPTS) $(REGRESS)
 
 .PHONY: submake
 submake:
diff --git a/src/pl/plpython/Makefile b/src/pl/plpython/Makefile
index 0fb120461cdca15f49c73011fc3d6ef75121870e..0afc08f798512d2b38d2dc68945bfac72238ee98 100644
--- a/src/pl/plpython/Makefile
+++ b/src/pl/plpython/Makefile
@@ -1,4 +1,4 @@
-# $PostgreSQL: pgsql/src/pl/plpython/Makefile,v 1.30 2008/10/01 22:38:56 petere Exp $
+# $PostgreSQL: pgsql/src/pl/plpython/Makefile,v 1.31 2008/10/02 08:11:11 petere Exp $
 
 subdir = src/pl/plpython
 top_builddir = ../../..
@@ -73,7 +73,7 @@ installdirs: installdirs-lib
 uninstall: uninstall-lib
 
 installcheck: submake
-	$(top_builddir)/src/test/regress/pg_regress --psqldir=$(PSQLDIR) $(REGRESS_OPTS) $(REGRESS)
+	$(top_builddir)/src/test/regress/pg_regress --inputdir=$(srcdir) --psqldir=$(PSQLDIR) $(REGRESS_OPTS) $(REGRESS)
 
 .PHONY: submake
 submake:
diff --git a/src/pl/tcl/Makefile b/src/pl/tcl/Makefile
index 9847babec9d10e8c348b68f4ef4c74586e4a03ea..1b71c7c23195767cec22037473af49522aef0f84 100644
--- a/src/pl/tcl/Makefile
+++ b/src/pl/tcl/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for the pltcl shared object
 #
-# $PostgreSQL: pgsql/src/pl/tcl/Makefile,v 1.52 2008/10/01 22:38:56 petere Exp $
+# $PostgreSQL: pgsql/src/pl/tcl/Makefile,v 1.53 2008/10/02 08:11:11 petere Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -59,7 +59,7 @@ uninstall: uninstall-lib
 	$(MAKE) -C modules $@
 
 installcheck: submake
-	$(top_builddir)/src/test/regress/pg_regress --psqldir=$(PSQLDIR) $(REGRESS_OPTS) $(REGRESS)
+	$(top_builddir)/src/test/regress/pg_regress --inputdir=$(srcdir) --psqldir=$(PSQLDIR) $(REGRESS_OPTS) $(REGRESS)
 
 .PHONY: submake
 submake: