diff --git a/Mac/BuildScript/build-installer.py b/Mac/BuildScript/build-installer.py
index d76b2c09676..b97d55bb030 100755
--- a/Mac/BuildScript/build-installer.py
+++ b/Mac/BuildScript/build-installer.py
@@ -162,7 +162,8 @@ def getTargetCompilers():
 
 CC, CXX = getTargetCompilers()
 
-PYTHON_3 = getVersionMajorMinor() >= (3, 0)
+PYTHON_2 = getVersionMajorMinor()[0] == 2
+PYTHON_3 = getVersionMajorMinor()[0] == 3
 
 USAGE = textwrap.dedent("""\
     Usage: build_python [options]
@@ -210,9 +211,9 @@ def library_recipes():
 
     result.extend([
           dict(
-              name="OpenSSL 1.0.2o",
-              url="https://www.openssl.org/source/openssl-1.0.2o.tar.gz",
-              checksum='44279b8557c3247cbe324e2322ecd114',
+              name="OpenSSL 1.0.2p",
+              url="https://www.openssl.org/source/openssl-1.0.2p.tar.gz",
+              checksum='ac5eb30bf5798aa14b1ae6d0e7da58df',
               buildrecipe=build_universal_openssl,
               configure=None,
               install=None,
@@ -607,9 +608,10 @@ def checkEnvironment():
         base_path = base_path + ':' + OLD_DEVELOPER_TOOLS
     os.environ['PATH'] = base_path
     print("Setting default PATH: %s"%(os.environ['PATH']))
-    # Ensure we have access to sphinx-build.
-    # You may have to create a link in /usr/bin for it.
-    runCommand('sphinx-build --version')
+    if PYTHON_2:
+        # Ensure we have access to sphinx-build.
+        # You may have to define SDK_TOOLS_BIN and link to it there,
+        runCommand('sphinx-build --version')
 
 def parseOptions(args=None):
     """
@@ -822,6 +824,13 @@ def build_universal_openssl(basedir, archList):
         ]
         if no_asm:
             configure_opts.append("no-asm")
+        # OpenSSL 1.0.2o broke the Configure test for whether the compiler
+        # in use supports dependency rule generation (cc -M) with gcc-4.2
+        # used for the 10.6+ installer builds.  Patch Configure here to
+        # force use of "cc -M" rather than "makedepend".
+        runCommand(
+            """sed -i "" 's|my $cc_as_makedepend = 0|my $cc_as_makedepend = 1|g' Configure""")
+
         runCommand(" ".join(["perl", "Configure"]
                         + arch_opts[arch] + configure_opts))
         runCommand("make depend")
@@ -1055,9 +1064,14 @@ def buildPythonDocs():
     curDir = os.getcwd()
     os.chdir(buildDir)
     runCommand('make clean')
-    # Create virtual environment for docs builds with blurb and sphinx
-    runCommand('make venv')
-    runCommand('make html PYTHON=venv/bin/python')
+    if PYTHON_2:
+        # Python 2 doc builds do not use blurb nor do they have a venv target.
+        # Assume sphinx-build is on our PATH, checked in checkEnvironment
+        runCommand('make html')
+    else:
+        # Create virtual environment for docs builds with blurb and sphinx
+        runCommand('make venv')
+        runCommand('make html PYTHON=venv/bin/python')
     os.chdir(curDir)
     if not os.path.exists(docdir):
         os.mkdir(docdir)
diff --git a/Misc/NEWS.d/next/macOS/2018-09-11-08-47-50.bpo-34405.f1-fT5.rst b/Misc/NEWS.d/next/macOS/2018-09-11-08-47-50.bpo-34405.f1-fT5.rst
new file mode 100644
index 00000000000..e9237004d23
--- /dev/null
+++ b/Misc/NEWS.d/next/macOS/2018-09-11-08-47-50.bpo-34405.f1-fT5.rst
@@ -0,0 +1 @@
+Update to OpenSSL 1.0.2p for macOS installer builds.