diff --git a/.gitignore b/.gitignore
index bade7f08c..07589aa00 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,9 +2,14 @@
 build/
 out/
 .idea/
+.vscode/
 
 # Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
 !gradle-wrapper.jar
 
 # Cache of project
 .gradletasknamecache
+
+# Generated by javac -h and runtime
+*.class
+*.log
diff --git a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/operations/Algebra.kt b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/operations/Algebra.kt
index 201e39314..572f7089a 100644
--- a/kmath-core/src/commonMain/kotlin/space/kscience/kmath/operations/Algebra.kt
+++ b/kmath-core/src/commonMain/kotlin/space/kscience/kmath/operations/Algebra.kt
@@ -175,6 +175,7 @@ public interface SpaceOperations<T> : Algebra<T> {
      * @param k the divisor.
      * @return the quotient.
      */
+    @Deprecated("Dividing not allowed in a Ring")
     public operator fun T.div(k: Number): T = multiply(this, 1.0 / k.toDouble())
 
     /**
diff --git a/kmath-nd4j/src/main/kotlin/space/kscience/kmath/nd4j/Nd4jArrayAlgebra.kt b/kmath-nd4j/src/main/kotlin/space/kscience/kmath/nd4j/Nd4jArrayAlgebra.kt
index 1e9818a4a..c50174b95 100644
--- a/kmath-nd4j/src/main/kotlin/space/kscience/kmath/nd4j/Nd4jArrayAlgebra.kt
+++ b/kmath-nd4j/src/main/kotlin/space/kscience/kmath/nd4j/Nd4jArrayAlgebra.kt
@@ -96,6 +96,7 @@ public interface Nd4jArraySpace<T, S : Space<T>> : NDSpace<T, S>, Nd4jArrayAlgeb
         return a.ndArray.mul(k).wrap()
     }
 
+    @Deprecated("Avoid using this method, underlying array get casted to Doubles")
     public override operator fun NDStructure<T>.div(k: Number): Nd4jArrayStructure<T> {
         return ndArray.div(k).wrap()
     }