diff --git a/cibuildwheel/__main__.py b/cibuildwheel/__main__.py
index 13fcc881..6c3963ff 100644
--- a/cibuildwheel/__main__.py
+++ b/cibuildwheel/__main__.py
@@ -168,65 +168,38 @@ def main():
     )
 
     if platform == 'linux':
-        manylinux_x86_64_image = os.environ.get('CIBW_MANYLINUX_X86_64_IMAGE', 'manylinux2010')
-        manylinux_i686_image = os.environ.get('CIBW_MANYLINUX_I686_IMAGE', 'manylinux2010')
-        manylinux_pypy_x86_64_image = os.environ.get('CIBW_MANYLINUX_PYPY_X86_64_IMAGE', 'manylinux2010')
-        manylinux_aarch64_image = os.environ.get('CIBW_MANYLINUX_AARCH64_IMAGE', 'manylinux2014')
-        manylinux_ppc64le_image = os.environ.get('CIBW_MANYLINUX_PPC64LE_IMAGE', 'manylinux2014')
-        manylinux_s390x_image = os.environ.get('CIBW_MANYLINUX_S390X_IMAGE', 'manylinux2014')
-
         pinned_docker_images_file = os.path.join(
             os.path.dirname(__file__), 'resources', 'pinned_docker_images.cfg'
         )
-        pinned_docker_images = ConfigParser()
-        pinned_docker_images.read(pinned_docker_images_file)
-
-        # pinned_docker_images looks like a dict of dicts, e.g.
-        # { 'manylinux1': {'x86_64': '...', 'i686': '...'},
-        #   'manylinux2010': {'x86_64': '...', 'i686': '...'},
-        #   'manylinux2014': {'x86_64': '...', 'i686': '...'} }
+        all_pinned_docker_images = ConfigParser()
+        all_pinned_docker_images.read(pinned_docker_images_file)
+        # all_pinned_docker_images looks like a dict of dicts, e.g.
+        # { 'x86_64': {'manylinux1': '...', 'manylinux2010': '...', 'manylinux2014': '...'},
+        #   'i686': {'manylinux1': '...', 'manylinux2010': '...', 'manylinux2014': '...'},
+        #   'pypy_x86_64': {'manylinux2010': '...' }
+        #   ... }
 
         manylinux_images = {}
 
-        if manylinux_x86_64_image in pinned_docker_images:
-            manylinux_images['x86_64'] = pinned_docker_images[manylinux_x86_64_image]['x86_64']
-        else:
-            manylinux_images['x86_64'] = manylinux_x86_64_image
+        for build_platform in ['x86_64', 'i686', 'pypy_x86_64', 'aarch64', 'ppc64le', 's390x']:
+            pinned_images = all_pinned_docker_images[build_platform]
 
-        if manylinux_i686_image in pinned_docker_images:
-            manylinux_images['i686'] = pinned_docker_images[manylinux_i686_image]['i686']
-        else:
-            manylinux_images['i686'] = manylinux_i686_image
+            config_name = 'CIBW_MANYLINUX_{}_IMAGE'.format(build_platform.upper())
+            config_value = os.environ.get(config_name)
 
-        if manylinux_pypy_x86_64_image in pinned_docker_images:
-            manylinux_images['pypy_x86_64'] = pinned_docker_images[manylinux_pypy_x86_64_image]['pypy_x86_64']
-        else:
-            manylinux_images['pypy_x86_64'] = manylinux_pypy_x86_64_image
+            if config_value is None:
+                # default to manylinux2010 if it's available, otherwise manylinux2014
+                image = pinned_images.get('manylinux2010') or pinned_images.get('manylinux2014')
+            elif config_value in pinned_images:
+                image = pinned_images[config_value]
+            else:
+                image = config_value
 
-        if manylinux_aarch64_image in pinned_docker_images:
-            manylinux_images['aarch64'] = pinned_docker_images[manylinux_aarch64_image]['aarch64']
-        else:
-            manylinux_images['aarch64'] = manylinux_aarch64_image
-
-        if manylinux_ppc64le_image in pinned_docker_images:
-            manylinux_images['ppc64le'] = pinned_docker_images[manylinux_ppc64le_image]['ppc64le']
-        else:
-            manylinux_images['ppc64le'] = manylinux_ppc64le_image
-
-        if manylinux_s390x_image in pinned_docker_images:
-            manylinux_images['x390x'] = pinned_docker_images[manylinux_s390x_image]['x390x']
-        else:
-            manylinux_images['x390x'] = manylinux_s390x_image
-
-        manylinux_images['pypy_x86_64'] = ''
+            manylinux_images[build_platform] = image
 
         build_options.update(
             manylinux_images=manylinux_images
         )
-    elif platform == 'macos':
-        pass
-    elif platform == 'windows':
-        pass
 
     # Python is buffering by default when running on the CI platforms, giving problems interleaving subprocess call output with unflushed calls to 'print'
     sys.stdout = Unbuffered(sys.stdout)