diff --git a/gravity.h b/gravity.h
index 9fcd110..c784a9f 100644
--- a/gravity.h
+++ b/gravity.h
@@ -3,16 +3,16 @@
 
 #include "balls.h"
 
-extern void gravity_constant_field (double x, double y);
-extern void gravity_newton_field (double r, double g);
+extern void gravity_constant_field(double x, double y);
+extern void gravity_newton_field(double r, double g);
 
-extern vec2d gravity_vector (const ball * b);
+extern vec2d gravity_vector(const ball* b);
 
-extern void gravity_draw_visible_field (cairo_t * cr);
+extern void gravity_draw_visible_field(cairo_t* cr);
 
-extern void gravity_draw (cairo_t * cr);
-extern void gravity_change (double dx, double dy);
+extern void gravity_draw(cairo_t* cr);
+extern void gravity_change(double dx, double dy);
 
-extern void gravity_collisions (ball * begin, ball * end);
+extern void gravity_collisions(ball* begin, ball* end);
 
 #endif