diff --git a/src/graphics.hpp b/src/graphics.hpp
index b9dbf163..85950208 100644
--- a/src/graphics.hpp
+++ b/src/graphics.hpp
@@ -315,7 +315,7 @@ class Camera {
 		dis = 0.5f*(float)width/tan(fov*pif/360.0f);
 	}
 	void input_N() {
-		eye_distance = fmax(eye_distance-0.2f, 0.0f);
+		eye_distance = eye_distance-0.2f;
 	}
 	void input_M() {
 		eye_distance += 0.2f;
@@ -362,4 +362,4 @@ void draw_triangle(const float3& p0, const float3& p1, const float3& p2, const i
 void draw_triangle(const float3& p0, const float3& p1, const float3& p2, const int c0, const int c1, const int c2, const bool translucent=false);
 void draw_text(const float3& p, const float r, const string& s, const int color);
 
-#endif // GRAPHICS
\ No newline at end of file
+#endif // GRAPHICS