diff --git a/src/core/operations/GenerateDeBruijnSequence.mjs b/src/core/operations/GenerateDeBruijnSequence.mjs
index f28d421f..73174af4 100644
--- a/src/core/operations/GenerateDeBruijnSequence.mjs
+++ b/src/core/operations/GenerateDeBruijnSequence.mjs
@@ -50,6 +50,10 @@ class GenerateDeBruijnSequence extends Operation {
             throw new OperationError("Invalid alphabet size, required to be between 2 and 9 (inclusive).");
         }
 
+        if (!Number.isInteger(k)) {
+            throw new OperationError("Invalid alphabet size, required to be integer.");
+        }
+
         if (n < 2) {
             throw new OperationError("Invalid key length, required to be at least 2.");
         }