diff --git a/gallery_dl/downloader/http.py b/gallery_dl/downloader/http.py
index 8e112dc6..fb824361 100644
--- a/gallery_dl/downloader/http.py
+++ b/gallery_dl/downloader/http.py
@@ -186,16 +186,19 @@ class HttpDownloader(DownloaderBase):
                         size, self.maxsize)
                     return False
 
+            build_path = False
+
             # set missing filename extension from MIME type
             if not pathfmt.extension:
                 pathfmt.set_extension(self._find_extension(response))
-                if pathfmt.exists():
-                    pathfmt.temppath = ""
-                    return True
+                build_path = True
 
             # set metadata from HTTP headers
             if self.metadata:
                 kwdict[self.metadata] = util.extract_headers(response)
+                build_path = True
+
+            if build_path:
                 pathfmt.build_path()
                 if pathfmt.exists():
                     pathfmt.temppath = ""
@@ -328,6 +331,7 @@ class HttpDownloader(DownloaderBase):
             for ext, check in SIGNATURE_CHECKS.items():
                 if check(file_header):
                     pathfmt.set_extension(ext)
+                    pathfmt.build_path()
                     return True
         return False
 
diff --git a/gallery_dl/downloader/ytdl.py b/gallery_dl/downloader/ytdl.py
index efa957b4..c44ea0a5 100644
--- a/gallery_dl/downloader/ytdl.py
+++ b/gallery_dl/downloader/ytdl.py
@@ -98,6 +98,7 @@ class YoutubeDLDownloader(DownloaderBase):
                 pathfmt.realdirectory + filename)
         else:
             pathfmt.set_extension(info_dict["ext"])
+            pathfmt.build_path()
 
         if pathfmt.exists():
             pathfmt.temppath = ""
@@ -118,6 +119,7 @@ class YoutubeDLDownloader(DownloaderBase):
 
     def _download_playlist(self, ytdl_instance, pathfmt, info_dict):
         pathfmt.set_extension("%(playlist_index)s.%(ext)s")
+        pathfmt.build_path()
         self._set_outtmpl(ytdl_instance, pathfmt.realpath)
 
         for entry in info_dict["entries"]:
diff --git a/gallery_dl/job.py b/gallery_dl/job.py
index c03a7c90..2d8ab4ef 100644
--- a/gallery_dl/job.py
+++ b/gallery_dl/job.py
@@ -232,11 +232,14 @@ class DownloadJob(Job):
             self.handle_skip()
             return
 
-        if pathfmt.exists():
-            if archive:
-                archive.add(kwdict)
-            self.handle_skip()
-            return
+        if pathfmt.extension and not self.metadata_http:
+            pathfmt.build_path()
+
+            if pathfmt.exists():
+                if archive:
+                    archive.add(kwdict)
+                self.handle_skip()
+                return
 
         if self.sleep:
             self.extractor.sleep(self.sleep(), "download")
@@ -536,12 +539,11 @@ class SimulationJob(DownloadJob):
     def handle_url(self, url, kwdict):
         if not kwdict["extension"]:
             kwdict["extension"] = "jpg"
-        self.pathfmt.set_filename(kwdict)
         if self.sleep:
             self.extractor.sleep(self.sleep(), "download")
         if self.archive:
             self.archive.add(kwdict)
-        self.out.skip(self.pathfmt.path)
+        self.out.skip(self.pathfmt.build_filename(kwdict))
 
     def handle_directory(self, kwdict):
         if not self.pathfmt:
diff --git a/gallery_dl/path.py b/gallery_dl/path.py
index 28c07c3c..efcacf6d 100644
--- a/gallery_dl/path.py
+++ b/gallery_dl/path.py
@@ -15,16 +15,16 @@ import functools
 from . import util, formatter, exception
 
 WINDOWS = util.WINDOWS
+EXTENSION_MAP = {
+    "jpeg": "jpg",
+    "jpe" : "jpg",
+    "jfif": "jpg",
+    "jif" : "jpg",
+    "jfi" : "jpg",
+}
 
 
 class PathFormat():
-    EXTENSION_MAP = {
-        "jpeg": "jpg",
-        "jpe" : "jpg",
-        "jfif": "jpg",
-        "jif" : "jpg",
-        "jfi" : "jpg",
-    }
 
     def __init__(self, extractor):
         config = extractor.config
@@ -78,7 +78,7 @@ class PathFormat():
 
         extension_map = config("extension-map")
         if extension_map is None:
-            extension_map = self.EXTENSION_MAP
+            extension_map = EXTENSION_MAP
         self.extension_map = extension_map.get
 
         restrict = config("path-restrict", "auto")
@@ -161,12 +161,14 @@ class PathFormat():
         num = 1
         try:
             while True:
-                self.prefix = str(num) + "."
-                self.set_extension(self.extension, False)
+                prefix = format(num) + "."
+                self.kwdict["extension"] = prefix + self.extension
+                self.build_path()
                 os.stat(self.realpath)  # raises OSError if file doesn't exist
                 num += 1
         except OSError:
             pass
+        self.prefix = prefix
         return False
 
     def set_directory(self, kwdict):
@@ -198,28 +200,21 @@ class PathFormat():
     def set_filename(self, kwdict):
         """Set general filename data"""
         self.kwdict = kwdict
-        self.temppath = self.prefix = ""
+        self.filename = self.temppath = self.prefix = ""
 
         ext = kwdict["extension"]
         kwdict["extension"] = self.extension = self.extension_map(ext, ext)
 
-        if self.extension:
-            self.build_path()
-        else:
-            self.filename = ""
-
     def set_extension(self, extension, real=True):
         """Set filename extension"""
-        extension = self.extension_map(extension, extension)
-        if real:
-            self.extension = extension
+        self.extension = extension = self.extension_map(extension, extension)
         self.kwdict["extension"] = self.prefix + extension
-        self.build_path()
 
     def fix_extension(self, _=None):
         """Fix filenames without a given filename extension"""
         if not self.extension:
-            self.set_extension("", False)
+            self.kwdict["extension"] = self.prefix + self.extension_map("", "")
+            self.build_path()
             if self.path[-1] == ".":
                 self.path = self.path[:-1]
                 self.temppath = self.realpath = self.realpath[:-1]
@@ -296,7 +291,9 @@ class PathFormat():
         if self.extension:
             self.temppath += ".part"
         else:
-            self.set_extension("part", False)
+            self.kwdict["extension"] = self.prefix + self.extension_map(
+                "part", "part")
+            self.build_path()
         if part_directory:
             self.temppath = os.path.join(
                 part_directory,
diff --git a/gallery_dl/postprocessor/compare.py b/gallery_dl/postprocessor/compare.py
index b3b94f7a..910e1d77 100644
--- a/gallery_dl/postprocessor/compare.py
+++ b/gallery_dl/postprocessor/compare.py
@@ -51,8 +51,9 @@ class ComparePP(PostProcessor):
         num = 1
         try:
             while not self._compare(pathfmt.realpath, pathfmt.temppath):
-                pathfmt.prefix = str(num) + "."
-                pathfmt.set_extension(pathfmt.extension, False)
+                pathfmt.prefix = prefix = format(num) + "."
+                pathfmt.kwdict["extension"] = prefix + pathfmt.extension
+                pathfmt.build_path()
                 num += 1
             return self._equal(pathfmt)
         except OSError:
diff --git a/gallery_dl/postprocessor/ugoira.py b/gallery_dl/postprocessor/ugoira.py
index 98c82468..9d2cb34e 100644
--- a/gallery_dl/postprocessor/ugoira.py
+++ b/gallery_dl/postprocessor/ugoira.py
@@ -90,15 +90,17 @@ class UgoiraPP(PostProcessor):
         if pathfmt.extension != "zip":
             return
 
-        if "frames" in pathfmt.kwdict:
-            self._frames = pathfmt.kwdict["frames"]
-        elif "pixiv_ugoira_frame_data" in pathfmt.kwdict:
-            self._frames = pathfmt.kwdict["pixiv_ugoira_frame_data"]["data"]
+        kwdict = pathfmt.kwdict
+        if "frames" in kwdict:
+            self._frames = kwdict["frames"]
+        elif "pixiv_ugoira_frame_data" in kwdict:
+            self._frames = kwdict["pixiv_ugoira_frame_data"]["data"]
         else:
             return
 
         if self.delete:
             pathfmt.set_extension(self.extension)
+            pathfmt.build_path()
 
     def convert(self, pathfmt):
         if not self._frames:
@@ -115,6 +117,8 @@ class UgoiraPP(PostProcessor):
 
             # process frames and collect command-line arguments
             pathfmt.set_extension(self.extension)
+            pathfmt.build_path()
+
             args = self._process(pathfmt, tempdir)
             if self.args:
                 args += self.args
@@ -151,6 +155,7 @@ class UgoiraPP(PostProcessor):
                     pathfmt.delete = True
                 else:
                     pathfmt.set_extension("zip")
+                    pathfmt.build_path()
 
     def _exec(self, args):
         self.log.debug(args)
diff --git a/test/test_downloader.py b/test/test_downloader.py
index 9d460c33..ae826a0f 100644
--- a/test/test_downloader.py
+++ b/test/test_downloader.py
@@ -131,6 +131,7 @@ class TestDownloaderBase(unittest.TestCase):
         pathfmt = cls.job.pathfmt
         pathfmt.set_directory(kwdict)
         pathfmt.set_filename(kwdict)
+        pathfmt.build_path()
 
         if content:
             mode = "w" + ("b" if isinstance(content, bytes) else "")
diff --git a/test/test_postprocessor.py b/test/test_postprocessor.py
index ba37ee08..7da2089d 100644
--- a/test/test_postprocessor.py
+++ b/test/test_postprocessor.py
@@ -97,6 +97,7 @@ class BasePostprocessorTest(unittest.TestCase):
         self.pathfmt = self.job.pathfmt
         self.pathfmt.set_directory(kwdict)
         self.pathfmt.set_filename(kwdict)
+        self.pathfmt.build_path()
 
         pp = postprocessor.find(self.__class__.__name__[:-4].lower())
         return pp(self.job, options)
@@ -118,6 +119,7 @@ class ClassifyTest(BasePostprocessorTest):
             for ext in exts
         })
         self.pathfmt.set_extension("jpg")
+        self.pathfmt.build_path()
 
         pp.prepare(self.pathfmt)
         path = os.path.join(self.dir.name, "test", "Pictures")
@@ -150,6 +152,7 @@ class ClassifyTest(BasePostprocessorTest):
             "bar": "foo/bar",
         })
         self.pathfmt.set_extension("foo")
+        self.pathfmt.build_path()
 
         pp.prepare(self.pathfmt)
         path = os.path.join(self.dir.name, "test", "foo", "bar")