diff --git a/src/main/kotlin/org/jetbrains/bio/viktor/F64Array.kt b/src/main/kotlin/org/jetbrains/bio/viktor/F64Array.kt
index 81aa408..7fe09a5 100644
--- a/src/main/kotlin/org/jetbrains/bio/viktor/F64Array.kt
+++ b/src/main/kotlin/org/jetbrains/bio/viktor/F64Array.kt
@@ -147,6 +147,19 @@ open class F64Array protected constructor(
         }
     }
 
+    @Suppress("nothing_to_inline")
+    private inline fun outOfBounds(indices: IntArray, shape: IntArray): Nothing {
+        val nDim = shape.size
+        val reason = when {
+            indices.size > nDim -> "too many indices"
+            indices.size < nDim -> "too few indices"
+            else -> "(${indices.joinToString(", ")}) out of bounds " +
+                    "for shape ${shape.joinToString(", ")}"
+        }
+
+        throw IndexOutOfBoundsException(reason)
+    }
+
     /**
      * Returns a sequence of views along the specified [axis].
      *
diff --git a/src/main/kotlin/org/jetbrains/bio/viktor/Internals.kt b/src/main/kotlin/org/jetbrains/bio/viktor/Internals.kt
index fd8c848..e671953 100644
--- a/src/main/kotlin/org/jetbrains/bio/viktor/Internals.kt
+++ b/src/main/kotlin/org/jetbrains/bio/viktor/Internals.kt
@@ -10,29 +10,16 @@ internal fun IntArray.remove(pos: Int) = when (pos) {
 }
 
 @Suppress("nothing_to_inline")
-inline fun checkIndex(label: String, pos: Int, size: Int) {
+internal inline fun checkIndex(label: String, pos: Int, size: Int) {
     if (pos < 0 || pos >= size) {
         throw IndexOutOfBoundsException("$label must be in [0, $size)")
     }
 }
 
 @Suppress("nothing_to_inline")
-inline fun check1D(a: F64Array) {
+internal inline fun check1D(a: F64Array) {
     check(a.nDim == 1) { "expected a 1-D array" }
 }
 
 @Suppress("nothing_to_inline")
-inline fun unsupported(): Nothing = throw UnsupportedOperationException()
-
-@Suppress("nothing_to_inline")
-internal inline fun outOfBounds(indices: IntArray, shape: IntArray): Nothing {
-    val nDim = shape.size
-    val reason = when {
-        indices.size > nDim -> "too many indices"
-        indices.size < nDim -> "too few indices"
-        else -> "(${indices.joinToString(", ")}) out of bounds " +
-                "for shape ${shape.joinToString(", ")}"
-    }
-
-    throw IndexOutOfBoundsException(reason)
-}
\ No newline at end of file
+internal inline fun unsupported(): Nothing = throw UnsupportedOperationException()
\ No newline at end of file