diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index bfc838f48f2..5e92f1ac2e0 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,7 @@
+2019-12-22  Maciej W. Rozycki  <macro@wdc.com>
+
+	* gcc-interface/Makefile.in (toolexeclibdir): New variable.
+
 2019-12-18  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc-interface/trans.c (Pragma_to_gnu) <Pragma_Warnings>: Push a
diff --git a/gcc/ada/gcc-interface/Makefile.in b/gcc/ada/gcc-interface/Makefile.in
index 8deffb6eb36..3342e33b4b1 100644
--- a/gcc/ada/gcc-interface/Makefile.in
+++ b/gcc/ada/gcc-interface/Makefile.in
@@ -880,6 +880,12 @@ b_gnatm.o : b_gnatm.adb
 	$(CC) -c $(ALL_ADAFLAGS) $(ADA_INCLUDES) -gnatws -gnatyN \
 	    $< $(OUTPUT_OPTION)
 
+# Provide a `toolexeclibdir' definition for when `gnat-install-lib' is
+# wired through gcc/ in a configuration with top-level libada disabled.
+# It will be overridden with the value configured when `gnat-install-lib'
+# is invoked through libada/.
+toolexeclibdir = $(ADA_RTL_OBJ_DIR)
+
 ADA_INCLUDE_DIR = $(libsubdir)/adainclude
 ADA_RTL_OBJ_DIR = $(libsubdir)/adalib
 ADA_RTL_DSO_DIR = $(toolexeclibdir)