diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 490fda857..62d4c0535 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index a4b442974..622ab64a3 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.5-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index 2fe81a7d9..fbd7c5158 100755
--- a/gradlew
+++ b/gradlew
@@ -82,6 +82,7 @@ esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
+
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
@@ -129,6 +130,7 @@ fi
 if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
     APP_HOME=`cygpath --path --mixed "$APP_HOME"`
     CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    
     JAVACMD=`cygpath --unix "$JAVACMD"`
 
     # We build the pattern for arguments to be converted via cygpath
diff --git a/gradlew.bat b/gradlew.bat
index 62bd9b9cc..5093609d5 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -84,6 +84,7 @@ set CMD_LINE_ARGS=%*
 
 set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
+
 @rem Execute Gradle
 "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
 
diff --git a/kmath-core/src/commonMain/kotlin/scientifik/kmath/operations/NumberAlgebra.kt b/kmath-core/src/commonMain/kotlin/scientifik/kmath/operations/NumberAlgebra.kt
index 9639e4c28..2b6a92f14 100644
--- a/kmath-core/src/commonMain/kotlin/scientifik/kmath/operations/NumberAlgebra.kt
+++ b/kmath-core/src/commonMain/kotlin/scientifik/kmath/operations/NumberAlgebra.kt
@@ -102,7 +102,7 @@ object IntRing : Ring<Int>, Norm<Int, Int> {
     override val zero: Int = 0
     override inline fun add(a: Int, b: Int) = a + b
     override inline fun multiply(a: Int, b: Int) = a * b
-    override inline fun multiply(a: Int, k: Number) = (k * a)
+    override inline fun multiply(a: Int, k: Number) = k.toInt() * a
     override val one: Int = 1
 
     override inline fun norm(arg: Int) = abs(arg)
@@ -124,7 +124,7 @@ object ShortRing : Ring<Short>, Norm<Short, Short> {
     override val zero: Short = 0
     override inline fun add(a: Short, b: Short) = (a + b).toShort()
     override inline fun multiply(a: Short, b: Short) = (a * b).toShort()
-    override inline fun multiply(a: Short, k: Number) = (a * k)
+    override inline fun multiply(a: Short, k: Number) = (a * k.toShort()).toShort()
     override val one: Short = 1
 
     override fun norm(arg: Short): Short = if (arg > 0) arg else (-arg).toShort()
@@ -146,7 +146,7 @@ object ByteRing : Ring<Byte>, Norm<Byte, Byte> {
     override val zero: Byte = 0
     override inline fun add(a: Byte, b: Byte) = (a + b).toByte()
     override inline fun multiply(a: Byte, b: Byte) = (a * b).toByte()
-    override inline fun multiply(a: Byte, k: Number) = (a * k)
+    override inline fun multiply(a: Byte, k: Number) = (a * k.toByte()).toByte()
     override val one: Byte = 1
 
     override fun norm(arg: Byte): Byte = if (arg > 0) arg else (-arg).toByte()
@@ -168,7 +168,7 @@ object LongRing : Ring<Long>, Norm<Long, Long> {
     override val zero: Long = 0
     override inline fun add(a: Long, b: Long) = (a + b)
     override inline fun multiply(a: Long, b: Long) = (a * b)
-    override inline fun multiply(a: Long, k: Number) = (a * k)
+    override inline fun multiply(a: Long, k: Number) = a * k.toLong()
     override val one: Long = 1
 
     override fun norm(arg: Long): Long = abs(arg)
@@ -180,4 +180,4 @@ object LongRing : Ring<Long>, Norm<Long, Long> {
     override inline fun Long.minus(b: Long) = (this - b)
 
     override inline fun Long.times(b: Long) = (this * b)
-}
\ No newline at end of file
+}