diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index cbc0b86c9..e691897de 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -11,28 +11,28 @@ on:
     branches: [ master ]
 
 jobs:
-  java8:
-    name: Build with Java 8
+  java9:
+    name: Build with Java 9
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 8
+    - name: Set up JDK 9
       uses: actions/setup-java@v1
       with:
-        java-version: 8
+        java-version: 9
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
     - name: Build with Gradle
       run: ./gradlew check
-  java9:
-    name: Build with Java 9
+  java10:
+    name: Build with Java 10
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: Set up JDK 9
+    - name: Set up JDK 10
       uses: actions/setup-java@v1
       with:
-        java-version: 9
+        java-version: 10
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
     - name: Build with Gradle
@@ -40,14 +40,14 @@ jobs:
 
   integration:
     name: Integration test
-    needs: [java8]
+    needs: [java9]
     runs-on: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v2
       - run: git fetch --depth=1 origin +refs/tags/*:refs/tags/*
       - uses: actions/setup-java@v1
         with:
-          java-version: 8
+          java-version: 9
       - name: Grant execute permission for gradlew
         run: chmod +x gradlew
       - name: Build with Gradle
diff --git a/.java-version b/.java-version
new file mode 100644
index 000000000..ec635144f
--- /dev/null
+++ b/.java-version
@@ -0,0 +1 @@
+9
diff --git a/build.gradle b/build.gradle
index f92ba6770..9a9c910dc 100644
--- a/build.gradle
+++ b/build.gradle
@@ -15,7 +15,6 @@ plugins {
   id 'ru.vyarus.java-lib' version '1.0.5'
   // id 'ru.vyarus.pom' version '1.0.3'
   id 'ru.vyarus.github-info' version '1.1.0'
-  id 'ru.vyarus.animalsniffer' version '1.5.0'
 }
 
 group = "com.hierynomus"
@@ -39,17 +38,12 @@ repositories {
   mavenCentral()
 }
 
-sourceCompatibility = 1.7
-targetCompatibility = 1.7
-
 configurations.compile.transitive = false
 
 def bouncycastleVersion = "1.65"
 def sshdVersion = "2.1.0"
 
 dependencies {
-  signature 'org.codehaus.mojo.signature:java16:1.1@signature'
-
   implementation "org.slf4j:slf4j-api:1.7.7"
   implementation "org.bouncycastle:bcprov-jdk15on:$bouncycastleVersion"
   implementation "org.bouncycastle:bcpkix-jdk15on:$bouncycastleVersion"
@@ -78,6 +72,10 @@ license {
   excludes(['**/djb/Curve25519.java', '**/sshj/common/Base64.java', '**/org/mindrot/jbcrypt/*.java'])
 }
 
+if (!JavaVersion.current().isJava9Compatible()) {
+  throw new GradleScriptException("Minimum compilation version is Java 9")
+}
+
 // This disables the pedantic doclint feature of JDK8
 if (JavaVersion.current().isJava8Compatible()) {
   tasks.withType(Javadoc) {
@@ -85,6 +83,11 @@ if (JavaVersion.current().isJava8Compatible()) {
   }
 }
 
+
+compileJava {
+  options.compilerArgs.addAll(['--release', '7'])
+}
+
 task writeSshjVersionProperties {
   doLast {
     project.file("${project.buildDir}/resources/main").mkdirs()
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 29953ea14..490fda857 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 5b3f9ca6b..4c5803d13 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionSha256Sum=038794feef1f4745c6347107b6726279d1c824f3fc634b60f86ace1e9fbd1768
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index cccdd3d51..2fe81a7d9 100755
--- a/gradlew
+++ b/gradlew
@@ -1,5 +1,21 @@
 #!/usr/bin/env sh
 
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
 ##############################################################################
 ##
 ##  Gradle start up script for UN*X
@@ -28,7 +44,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
@@ -109,8 +125,8 @@ if $darwin; then
     GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
 fi
 
-# For Cygwin, switch paths to Windows format before running java
-if $cygwin ; then
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
     APP_HOME=`cygpath --path --mixed "$APP_HOME"`
     CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
     JAVACMD=`cygpath --unix "$JAVACMD"`
@@ -138,19 +154,19 @@ if $cygwin ; then
         else
             eval `echo args$i`="\"$arg\""
         fi
-        i=$((i+1))
+        i=`expr $i + 1`
     done
     case $i in
-        (0) set -- ;;
-        (1) set -- "$args0" ;;
-        (2) set -- "$args0" "$args1" ;;
-        (3) set -- "$args0" "$args1" "$args2" ;;
-        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
     esac
 fi
 
@@ -159,14 +175,9 @@ save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }
-APP_ARGS=$(save "$@")
+APP_ARGS=`save "$@"`
 
 # Collect all arguments for the java command, following the shell quoting and substitution rules
 eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
 
-# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
-if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
-  cd "$(dirname "$0")"
-fi
-
 exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
index f9553162f..62bd9b9cc 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -1,3 +1,19 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
 @if "%DEBUG%" == "" @echo off
 @rem ##########################################################################
 @rem
@@ -13,8 +29,11 @@ if "%DIRNAME%" == "" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
 
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome
diff --git a/src/test/java/net/schmizz/sshj/common/StreamCopierTest.java b/src/test/java/net/schmizz/sshj/common/StreamCopierTest.java
index c56dd2cc9..0b8ed95f2 100644
--- a/src/test/java/net/schmizz/sshj/common/StreamCopierTest.java
+++ b/src/test/java/net/schmizz/sshj/common/StreamCopierTest.java
@@ -44,6 +44,6 @@ public void copy() throws IOException {
         long copied = streamCopier.copy();
         assertThat(copied, is(1024L));
 
-        verify(logger).debug(contains("1.0 KiB transferred"));
+        verify(logger).debug(matches("^1[.,]0 KiB transferred.*$"));
     }
 }