--- a/Triangulate.c
+++ b/Triangulate.c
@@ -422,8 +422,8 @@
 	
 	A = ((t->v[2].x - t->v[0].x) * (t->v[1].y - t->v[0].y) - 
 	  	 (t->v[2].y - t->v[0].y) * (t->v[1].x - t->v[0].x))/2.0; 
-
-	return abs( A );	
+	// use fabs rather than abs as precision is lost with abs on 64bit platforms
+	return fabs( A );	
 }