diff --git a/slurm-spank-stunnel.c b/slurm-spank-stunnel.c
index b79cea0..c135bf5 100644
--- a/slurm-spank-stunnel.c
+++ b/slurm-spank-stunnel.c
@@ -41,6 +41,10 @@
 #include <arpa/inet.h>
 #include <errno.h>
 
+#ifndef SLURM_BACKWARD_COMPAT
+#define SLURM_BACKWARD_COMPAT 1
+#endif
+
 #include <slurm/slurm.h>
 #include <slurm/spank.h>