diff --git a/include/vectorial/vec2f.h b/include/vectorial/vec2f.h
index 8eccef9..4da3bb1 100644
--- a/include/vectorial/vec2f.h
+++ b/include/vectorial/vec2f.h
@@ -4,6 +4,7 @@
   Licensed under the terms of the two-clause BSD License (see LICENSE)
 */
 #ifndef VECTORIAL_VEC2F_H
+#define VECTORIAL_VEC2F_H
 
 #ifndef VECTORIAL_SIMD4F_H
   #include "vectorial/simd4f.h"
diff --git a/include/vectorial/vec3f.h b/include/vectorial/vec3f.h
index c52e7d5..ab46caa 100644
--- a/include/vectorial/vec3f.h
+++ b/include/vectorial/vec3f.h
@@ -5,6 +5,7 @@
   Licensed under the terms of the two-clause BSD License (see LICENSE)
 */
 #ifndef VECTORIAL_VEC3F_H
+#define VECTORIAL_VEC3F_H
 
 #ifndef VECTORIAL_SIMD4F_H
   #include "vectorial/simd4f.h"