diff --git a/Makefile.am b/Makefile.am
index ca5e189d3..e54202748 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -210,6 +210,7 @@ TESTS_ENVIRONMENT = \
 	PATH=$(abs_top_builddir)/tests/gpgscm:$(PATH) \
 	abs_top_srcdir=$(abs_top_srcdir) \
 	objdir=$(abs_top_builddir) \
+	GNUPG_BUILD_ROOT="$(abs_top_builddir)" \
 	GPGSCM_PATH=$(abs_top_srcdir)/tests/gpgscm
 
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