diff --git a/sphinx/builders/__init__.py b/sphinx/builders/__init__.py
index d52a7983d..ee55830fc 100644
--- a/sphinx/builders/__init__.py
+++ b/sphinx/builders/__init__.py
@@ -70,6 +70,10 @@ class Builder(object):
 
         # images that need to be copied over (source -> dest)
         self.images = {}
+        # basename of images directory
+        imagedir = ""
+        # relative path to image directory from current docname (used at writing docs)
+        imgpath = ""
 
         # these get set later
         self.parallel_ok = False
diff --git a/sphinx/builders/epub.py b/sphinx/builders/epub.py
index 5f9f66431..848dfaa43 100644
--- a/sphinx/builders/epub.py
+++ b/sphinx/builders/epub.py
@@ -404,7 +404,7 @@ class EpubBuilder(StandaloneHTMLBuilder):
         The method tries to read and write the files with the PIL,
         converting the format and resizing the image if necessary/possible.
         """
-        ensuredir(path.join(self.outdir, '_images'))
+        ensuredir(path.join(self.outdir, self.imagedir))
         for src in self.app.status_iterator(self.images, 'copying images... ',
                                             brown, len(self.images)):
             dest = self.images[src]
@@ -416,7 +416,7 @@ class EpubBuilder(StandaloneHTMLBuilder):
                               (path.join(self.srcdir, src), ))
                 try:
                     copyfile(path.join(self.srcdir, src),
-                             path.join(self.outdir, '_images', dest))
+                             path.join(self.outdir, self.imagedir, dest))
                 except (IOError, OSError) as err:
                     self.warn('cannot copy image file %r: %s' %
                               (path.join(self.srcdir, src), err))
@@ -432,7 +432,7 @@ class EpubBuilder(StandaloneHTMLBuilder):
                     nh = (height * nw) / width
                     img = img.resize((nw, nh), Image.BICUBIC)
             try:
-                img.save(path.join(self.outdir, '_images', dest))
+                img.save(path.join(self.outdir, self.imagedir, dest))
             except (IOError, OSError) as err:
                 self.warn('cannot write image file %r: %s' %
                           (path.join(self.srcdir, src), err))
diff --git a/sphinx/builders/html.py b/sphinx/builders/html.py
index d4bbefe49..d33d2eef4 100644
--- a/sphinx/builders/html.py
+++ b/sphinx/builders/html.py
@@ -95,6 +95,8 @@ class StandaloneHTMLBuilder(Builder):
         # a hash of all config values that, if changed, cause a full rebuild
         self.config_hash = ''
         self.tags_hash = ''
+        # basename of images directory
+        self.imagedir = '_images'
         # section numbers for headings in the currently visited document
         self.secnumbers = {}
         # currently written docname
@@ -437,7 +439,7 @@ class StandaloneHTMLBuilder(Builder):
         self.handle_page(docname, ctx, event_arg=doctree)
 
     def write_doc_serialized(self, docname, doctree):
-        self.imgpath = relative_uri(self.get_target_uri(docname), '_images')
+        self.imgpath = relative_uri(self.get_target_uri(docname), self.imagedir)
         self.post_process_images(doctree)
         title = self.env.longtitles.get(docname)
         title = title and self.render_partial(title)['title'] or ''
@@ -535,13 +537,13 @@ class StandaloneHTMLBuilder(Builder):
     def copy_image_files(self):
         # copy image files
         if self.images:
-            ensuredir(path.join(self.outdir, '_images'))
+            ensuredir(path.join(self.outdir, self.imagedir))
             for src in self.app.status_iterator(self.images, 'copying images... ',
                                                 brown, len(self.images)):
                 dest = self.images[src]
                 try:
                     copyfile(path.join(self.srcdir, src),
-                             path.join(self.outdir, '_images', dest))
+                             path.join(self.outdir, self.imagedir, dest))
                 except Exception as err:
                     self.warn('cannot copy image file %r: %s' %
                               (path.join(self.srcdir, src), err))
@@ -1029,6 +1031,7 @@ class SerializingHTMLBuilder(StandaloneHTMLBuilder):
     def init(self):
         self.config_hash = ''
         self.tags_hash = ''
+        self.imagedir = '_images'
         self.theme = None       # no theme necessary
         self.templates = None   # no template bridge necessary
         self.init_translator_class()
diff --git a/sphinx/builders/qthelp.py b/sphinx/builders/qthelp.py
index c0fff2a6a..8e2558e72 100644
--- a/sphinx/builders/qthelp.py
+++ b/sphinx/builders/qthelp.py
@@ -157,7 +157,7 @@ class QtHelpBuilder(StandaloneHTMLBuilder):
         olen = len(outdir)
         projectfiles = []
         staticdir = path.join(outdir, '_static')
-        imagesdir = path.join(outdir, '_images')
+        imagesdir = path.join(outdir, self.imagedir)
         for root, dirs, files in os.walk(outdir):
             resourcedir = root.startswith(staticdir) or \
                           root.startswith(imagesdir)
diff --git a/sphinx/builders/websupport.py b/sphinx/builders/websupport.py
index ed913945c..619ef6fe0 100644
--- a/sphinx/builders/websupport.py
+++ b/sphinx/builders/websupport.py
@@ -59,7 +59,7 @@ class WebSupportBuilder(PickleHTMLBuilder):
 
         self.secnumbers = self.env.toc_secnumbers.get(docname, {})
         self.fignumbers = self.env.toc_fignumbers.get(docname, {})
-        self.imgpath = '/' + posixpath.join(self.virtual_staticdir, '_images')
+        self.imgpath = '/' + posixpath.join(self.virtual_staticdir, self.imagedir)
         self.dlpath = '/' + posixpath.join(self.virtual_staticdir, '_downloads')
         self.current_docname = docname
         self.docwriter.write(doctree, destination)
@@ -71,7 +71,7 @@ class WebSupportBuilder(PickleHTMLBuilder):
         self.handle_page(docname, ctx, event_arg=doctree)
 
     def write_doc_serialized(self, docname, doctree):
-        self.imgpath = '/' + posixpath.join(self.virtual_staticdir, '_images')
+        self.imgpath = '/' + posixpath.join(self.virtual_staticdir, self.imagedir)
         self.post_process_images(doctree)
         title = self.env.longtitles.get(docname)
         title = title and self.render_partial(title)['title'] or ''
@@ -149,7 +149,7 @@ class WebSupportBuilder(PickleHTMLBuilder):
         PickleHTMLBuilder.handle_finish(self)
 
         # move static stuff over to separate directory
-        directories = ['_images', '_static']
+        directories = [self.imagedir, '_static']
         for directory in directories:
             src = path.join(self.outdir, directory)
             dst = path.join(self.staticdir, directory)
diff --git a/sphinx/ext/graphviz.py b/sphinx/ext/graphviz.py
index 56831c648..71e7ba651 100644
--- a/sphinx/ext/graphviz.py
+++ b/sphinx/ext/graphviz.py
@@ -146,14 +146,8 @@ def render_dot(self, code, options, format, prefix='graphviz'):
               ).encode('utf-8')
 
     fname = '%s-%s.%s' % (prefix, sha1(hashkey).hexdigest(), format)
-    if hasattr(self.builder, 'imgpath'):
-        # HTML
-        relfn = posixpath.join(self.builder.imgpath, fname)
-        outfn = path.join(self.builder.outdir, '_images', fname)
-    else:
-        # LaTeX
-        relfn = fname
-        outfn = path.join(self.builder.outdir, fname)
+    relfn = posixpath.join(self.builder.imgpath, fname)
+    outfn = path.join(self.builder.outdir, self.builder.imagedir, fname)
 
     if path.isfile(outfn):
         return relfn, outfn
diff --git a/sphinx/ext/pngmath.py b/sphinx/ext/pngmath.py
index 27d7978fe..81a6f9d57 100644
--- a/sphinx/ext/pngmath.py
+++ b/sphinx/ext/pngmath.py
@@ -86,7 +86,7 @@ def render_math(self, math):
 
     shasum = "%s.png" % sha1(latex.encode('utf-8')).hexdigest()
     relfn = posixpath.join(self.builder.imgpath, 'math', shasum)
-    outfn = path.join(self.builder.outdir, '_images', 'math', shasum)
+    outfn = path.join(self.builder.outdir, self.builder.imagedir, 'math', shasum)
     if path.isfile(outfn):
         depth = read_png_depth(outfn)
         return relfn, depth