diff --git a/src/main/kotlin/org/jetbrains/bio/viktor/F64Array.kt b/src/main/kotlin/org/jetbrains/bio/viktor/F64Array.kt
index 0684c97..7459bf4 100644
--- a/src/main/kotlin/org/jetbrains/bio/viktor/F64Array.kt
+++ b/src/main/kotlin/org/jetbrains/bio/viktor/F64Array.kt
@@ -112,7 +112,7 @@ open class F64Array protected constructor(
 
     operator fun get(d: Int, r: Int, c: Int): Double {
         check(nDim == 3) { "broadcasting get is not supported" }
-        checkIndex("depth", r, shape[0])
+        checkIndex("depth", d, shape[0])
         checkIndex("row", r, shape[1])
         checkIndex("column", c, shape[2])
         return data[unsafeIndex(d, r, c)]