diff --git a/autoconf.mk.in b/autoconf.mk.in
index 860fc4ab..cf7fa10f 100644
--- a/autoconf.mk.in
+++ b/autoconf.mk.in
@@ -37,4 +37,5 @@ BUILDRULES=@BUILDRULES@
 HAVE_LD_VERSION_SCRIPT=@HAVE_LD_VERSION_SCRIPT@
 WINDOWS_WORDSIZE=@WINDOWS_WORDSIZE@
 SHOW_FAILED_TEST_OUTPUT=@SHOW_FAILED_TEST_OUTPUT@
-LARGE_FILE_TEST_PATH=@LARGE_FILE_TEST_PATH@
+# Allow environment variable to override
+LARGE_FILE_TEST_PATH?=@LARGE_FILE_TEST_PATH@