diff --git a/src/wand/magick.rs b/src/wand/magick.rs
index 25b579e..8475bc5 100644
--- a/src/wand/magick.rs
+++ b/src/wand/magick.rs
@@ -257,8 +257,14 @@ impl MagickWand {
         gamma: f64,
         white_point: f64,
     ) -> Result<(), &'static str> {
-        let result =
-            unsafe { bindings::MagickLevelImage(self.wand, black_point, gamma, white_point) };
+        let result = unsafe {
+            bindings::MagickLevelImage(
+                self.wand,
+                black_point * bindings::QuantumRange,
+                gamma,
+                white_point * bindings::QuantumRange,
+            )
+        };
         match result {
             bindings::MagickBooleanType_MagickTrue => Ok(()),
             _ => Err("failed to set size of wand"),