diff --git a/services/std_svc/spm/el3_spmc/spmc_shared_mem.c b/services/std_svc/spm/el3_spmc/spmc_shared_mem.c
index 1e00982..6cc6b7d 100644
--- a/services/std_svc/spm/el3_spmc/spmc_shared_mem.c
+++ b/services/std_svc/spm/el3_spmc/spmc_shared_mem.c
@@ -196,6 +196,9 @@
 			uint32_t ffa_version, size_t *emad_size)
 {
 	uint8_t *emad;
+
+	assert(index < desc->emad_count);
+
 	/*
 	 * If the caller is using FF-A v1.0 interpret the descriptor as a v1.0
 	 * format, otherwise assume it is a v1.1 format.