diff --git a/include/lib/extensions/spe.h b/include/lib/extensions/spe.h
index d443f18..02fccae 100644
--- a/include/lib/extensions/spe.h
+++ b/include/lib/extensions/spe.h
@@ -13,10 +13,10 @@
 void spe_enable(bool el2_unused);
 void spe_disable(void);
 #else
-void spe_enable(bool el2_unused)
+static inline void spe_enable(bool el2_unused)
 {
 }
-void spe_disable(void)
+static inline void spe_disable(void)
 {
 }
 #endif