diff --git a/src/credits.c b/src/credits.c
index 20aef31..7e44251 100644
--- a/src/credits.c
+++ b/src/credits.c
@@ -4,6 +4,9 @@ static GLuint _pId = 0;
 static GLuint _texId = 0;
 static GLuint _quadId = 0;
 
+static const char matrix_modview[] = "modview";
+static const char matrix_proj[] = "proj";
+
 static void init(void);
 static void draw(void);
 
@@ -25,8 +28,8 @@ void credits(int state) {
 static void init(void) {
   _pId = gl4duCreateProgram("<vs>shaders/credits.vs", "<fs>shaders/credits.fs",
                             NULL);
-  gl4duGenMatrix(GL_FLOAT, "modview");
-  gl4duGenMatrix(GL_FLOAT, "proj");
+  gl4duGenMatrix(GL_FLOAT, matrix_modview);
+  gl4duGenMatrix(GL_FLOAT, matrix_proj);
   _quadId = gl4dgGenQuadf();
 
   // Code utilisé en tant qu'erreur de TTF_Font
@@ -66,11 +69,11 @@ static void draw(void) {
   d = -1.1f + .25f * t;
 
   GLfloat ratio = (GLfloat)_dims[0] / (GLfloat)_dims[1];
-  gl4duBindMatrix("proj");
+  gl4duBindMatrix(matrix_proj);
   gl4duLoadIdentityf();
   gl4duFrustumf(-ratio, ratio, -1, 1, 2, 100);
 
-  gl4duBindMatrix("modview");
+  gl4duBindMatrix(matrix_modview);
   gl4duLoadIdentityf();
 
   gl4duTranslatef(0.f, d, -2.f);