diff --git a/src/mesa/math/m_matrix.c b/src/mesa/math/m_matrix.c
index b3cfcd26a14..493d0e5cb27 100644
--- a/src/mesa/math/m_matrix.c
+++ b/src/mesa/math/m_matrix.c
@@ -131,7 +131,7 @@ static const char *types[] = {
 /**
  * Identity matrix.
  */
-static GLfloat Identity[16] = {
+static const GLfloat Identity[16] = {
    1.0, 0.0, 0.0, 0.0,
    0.0, 1.0, 0.0, 0.0,
    0.0, 0.0, 1.0, 0.0,