diff --git a/engines/freescape/shaders/freescape_triangle.fragment b/engines/freescape/shaders/freescape_triangle.fragment
index 2088bdc4357..9ad098b111e 100644
--- a/engines/freescape/shaders/freescape_triangle.fragment
+++ b/engines/freescape/shaders/freescape_triangle.fragment
@@ -8,8 +8,8 @@ varying vec4 var_color;
 void main()
 {
 	if (UBOOL_TEST(useStipple)) {
-		vec2 coord = ivec2(gl_FragCoord.xy - 0.5);
-		if (stipple[int(mod(coord.x, 8.) + mod(coord.y, 8.) * 8)] == 0)
+		ivec2 coord = ivec2(gl_FragCoord.xy - 0.5);
+		if (stipple[int(mod(float(coord.x), 8.) + mod(float(coord.y), 8.) * 8.)] == 0)
 			discard;
 	}