diff --git a/csharp/compatibility_tests/v3.0.0/test.sh b/csharp/compatibility_tests/v3.0.0/test.sh
index c381d7bc97..f893d64aba 100755
--- a/csharp/compatibility_tests/v3.0.0/test.sh
+++ b/csharp/compatibility_tests/v3.0.0/test.sh
@@ -40,7 +40,7 @@ TEST_VERSION=3.0.0
 # is also possible to use this same test set to test the compatibility of the
 # latest version against other versions.
 OLD_VERSION=$1
-OLD_VERSION_PROTOC=http://repo1.maven.org/maven2/com/google/protobuf/protoc/$OLD_VERSION/protoc-$OLD_VERSION-linux-x86_64.exe
+OLD_VERSION_PROTOC=https://repo1.maven.org/maven2/com/google/protobuf/protoc/$OLD_VERSION/protoc-$OLD_VERSION-linux-x86_64.exe
 
 echo "Running compatibility tests with $OLD_VERSION"
 
diff --git a/php/tests/compatibility_test.sh b/php/tests/compatibility_test.sh
index 8e1a75092b..2b5c6ab5b7 100755
--- a/php/tests/compatibility_test.sh
+++ b/php/tests/compatibility_test.sh
@@ -71,7 +71,7 @@ set -ex
 cd $(dirname $0)
 
 OLD_VERSION=$1
-OLD_VERSION_PROTOC=http://repo1.maven.org/maven2/com/google/protobuf/protoc/$OLD_VERSION/protoc-$OLD_VERSION-linux-x86_64.exe
+OLD_VERSION_PROTOC=https://repo1.maven.org/maven2/com/google/protobuf/protoc/$OLD_VERSION/protoc-$OLD_VERSION-linux-x86_64.exe
 
 # Extract the latest protobuf version number.
 VERSION_NUMBER=`grep "PHP_PROTOBUF_VERSION" ../ext/google/protobuf/protobuf.h | sed "s|#define PHP_PROTOBUF_VERSION \"\(.*\)\"|\1|"`
diff --git a/python/compatibility_tests/v2.5.0/test.sh b/python/compatibility_tests/v2.5.0/test.sh
index f983ea21d6..740c132556 100755
--- a/python/compatibility_tests/v2.5.0/test.sh
+++ b/python/compatibility_tests/v2.5.0/test.sh
@@ -15,7 +15,7 @@ TEST_VERSION=2.5.0
 # is also possible to use this same test set to test the compatibility of the
 # latest version against other versions.
 OLD_VERSION=$1
-OLD_VERSION_PROTOC=http://repo1.maven.org/maven2/com/google/protobuf/protoc/$OLD_VERSION/protoc-$OLD_VERSION-linux-x86_64.exe
+OLD_VERSION_PROTOC=https://repo1.maven.org/maven2/com/google/protobuf/protoc/$OLD_VERSION/protoc-$OLD_VERSION-linux-x86_64.exe
 
 # Extract the latest protobuf version number.
 VERSION_NUMBER=`grep "^__version__ = '.*'" ../../google/protobuf/__init__.py | sed "s|__version__ = '\(.*\)'|\1|"`
diff --git a/ruby/compatibility_tests/v3.0.0/test.sh b/ruby/compatibility_tests/v3.0.0/test.sh
index 996dc020c2..d5a8fd74d7 100755
--- a/ruby/compatibility_tests/v3.0.0/test.sh
+++ b/ruby/compatibility_tests/v3.0.0/test.sh
@@ -10,7 +10,7 @@ PROTOC_BINARY_NAME="protoc-3.0.0-linux-x86_64.exe"
 if [ `uname` = "Darwin" ]; then
   PROTOC_BINARY_NAME="protoc-3.0.0-osx-x86_64.exe"
 fi
-wget http://repo1.maven.org/maven2/com/google/protobuf/protoc/3.0.0/${PROTOC_BINARY_NAME} -O protoc
+wget https://repo1.maven.org/maven2/com/google/protobuf/protoc/3.0.0/${PROTOC_BINARY_NAME} -O protoc
 chmod +x protoc
 
 # Run tests