diff --git a/src/qhull/src/libqhull_r/user_r.h b/src/qhull/src/libqhull_r/user_r.h
index 7cca65a8043..fc105b9cace 100644
--- a/src/qhull/src/libqhull_r/user_r.h
+++ b/src/qhull/src/libqhull_r/user_r.h
@@ -139,7 +139,7 @@ Code flags --
    REALfloat =   1      all numbers are 'float' type
              =   0      all numbers are 'double' type
 */
-#define REALfloat 1
+#define REALfloat 0
 
 #if (REALfloat == 1)
 #define realT float