diff --git a/lib/jgit/jgit.bzl b/lib/jgit/jgit.bzl
index 8b9e83e6c6..8fe8b145a6 100644
--- a/lib/jgit/jgit.bzl
+++ b/lib/jgit/jgit.bzl
@@ -4,7 +4,7 @@ _JGIT_VERS = "5.1.7.201904200442-r"
 
 _DOC_VERS = _JGIT_VERS  # Set to _JGIT_VERS unless using a snapshot
 
-JGIT_DOC_URL = "http://download.eclipse.org/jgit/site/" + _DOC_VERS + "/apidocs"
+JGIT_DOC_URL = "https://download.eclipse.org/jgit/site/" + _DOC_VERS + "/apidocs"
 
 _JGIT_REPO = MAVEN_CENTRAL  # Leave here even if set to MAVEN_CENTRAL.
 
diff --git a/tools/bzl/javadoc.bzl b/tools/bzl/javadoc.bzl
index fcf9f336d6..638721053d 100644
--- a/tools/bzl/javadoc.bzl
+++ b/tools/bzl/javadoc.bzl
@@ -23,7 +23,7 @@ def _impl(ctx):
     transitive_jar_paths = [j.path for j in transitive_jars.to_list()]
     dir = ctx.outputs.zip.path + ".dir"
     source = ctx.outputs.zip.path + ".source"
-    external_docs = ["http://docs.oracle.com/javase/8/docs/api"] + ctx.attr.external_docs
+    external_docs = ["https://docs.oracle.com/javase/8/docs/api"] + ctx.attr.external_docs
     cmd = [
         "TZ=UTC",
         "export TZ",
diff --git a/tools/js/npm_pack.py b/tools/js/npm_pack.py
index f14262a7bd..57f31661c5 100755
--- a/tools/js/npm_pack.py
+++ b/tools/js/npm_pack.py
@@ -54,7 +54,7 @@ def main(args):
 
     name, version = args
     filename = '%s-%s.tgz' % (name, version)
-    url = 'http://registry.npmjs.org/%s/-/%s' % (name, filename)
+    url = 'https://registry.npmjs.org/%s/-/%s' % (name, filename)
 
     tmpdir = tempfile.mkdtemp()
     tgz = os.path.join(tmpdir, filename)
diff --git a/tools/util.py b/tools/util.py
index 172ecfe521..947e2c0a0f 100644
--- a/tools/util.py
+++ b/tools/util.py
@@ -16,9 +16,9 @@ from os import path
 
 REPO_ROOTS = {
   'ECLIPSE': 'https://repo.eclipse.org/content/groups/releases',
-  'GERRIT': 'http://gerrit-maven.storage.googleapis.com',
+  'GERRIT': 'https://gerrit-maven.storage.googleapis.com',
   'GERRIT_API': 'https://gerrit-api.commondatastorage.googleapis.com/release',
-  'MAVEN_CENTRAL': 'http://repo1.maven.org/maven2',
+  'MAVEN_CENTRAL': 'https://repo1.maven.org/maven2',
   'MAVEN_LOCAL': 'file://' + path.expanduser('~/.m2/repository'),
   'MAVEN_SNAPSHOT': 'https://oss.sonatype.org/content/repositories/snapshots',
 }
diff --git a/tools/util_test.py b/tools/util_test.py
index fa676966d8..1a389f552c 100644
--- a/tools/util_test.py
+++ b/tools/util_test.py
@@ -29,18 +29,18 @@ class TestResolveUrl(unittest.TestCase):
 
     def testKnownRedirect(self):
         url = resolve_url('MAVEN_CENTRAL:foo.jar',
-                          {'MAVEN_CENTRAL': 'http://my.company.mirror/maven2'})
-        self.assertEqual(url, 'http://my.company.mirror/maven2/foo.jar')
+                          {'MAVEN_CENTRAL': 'https://my.company.mirror/maven2'})
+        self.assertEqual(url, 'https://my.company.mirror/maven2/foo.jar')
 
     def testCustom(self):
-        url = resolve_url('http://maven.example.com/release/foo.jar', {})
-        self.assertEqual(url, 'http://maven.example.com/release/foo.jar')
+        url = resolve_url('https://maven.example.com/release/foo.jar', {})
+        self.assertEqual(url, 'https://maven.example.com/release/foo.jar')
 
     def testCustomRedirect(self):
         url = resolve_url('MAVEN_EXAMPLE:foo.jar',
                           {'MAVEN_EXAMPLE':
-                           'http://maven.example.com/release'})
-        self.assertEqual(url, 'http://maven.example.com/release/foo.jar')
+                           'https://maven.example.com/release'})
+        self.assertEqual(url, 'https://maven.example.com/release/foo.jar')
 
 
 if __name__ == '__main__':