diff --git a/zerver/lib/unminify.py b/zerver/lib/unminify.py
index 182b1c736c..1a99cd56b9 100644
--- a/zerver/lib/unminify.py
+++ b/zerver/lib/unminify.py
@@ -29,22 +29,23 @@ class SourceMap:
         out = ''  # type: str
         for ln in stacktrace.splitlines():
             out += ln + '\n'
-            match = re.search(r'/static/webpack-bundles/(.+)(\.[\.0-9a-f]+\.js):(\d+):(\d+)', ln)
+            match = re.search(r'/static/webpack-bundles/([^:]+):(\d+):(\d+)', ln)
             if match:
                 # Get the appropriate source map for the minified file.
-                minified_src = match.groups()[0] + match.groups()[1]
+                minified_src = match.groups()[0]
                 index = self._index_for(minified_src)
 
-                gen_line, gen_col = list(map(int, match.groups()[2:4]))
+                gen_line, gen_col = list(map(int, match.groups()[1:3]))
                 # The sourcemap lib is 0-based, so subtract 1 from line and col.
                 try:
                     result = index.lookup(line=gen_line-1, column=gen_col-1)
                     display_src = result.src
-                    webpack_prefix = "webpack:///"
-                    if display_src.startswith(webpack_prefix):
-                        display_src = display_src[len(webpack_prefix):]
-                    out += ('       = %s line %d column %d\n' %
-                            (display_src, result.src_line+1, result.src_col+1))
+                    if display_src is not None:
+                        webpack_prefix = "webpack:///"
+                        if display_src.startswith(webpack_prefix):
+                            display_src = display_src[len(webpack_prefix):]
+                        out += ('       = %s line %d column %d\n' %
+                                (display_src, result.src_line+1, result.src_col+1))
                 except IndexError:
                     out += '       [Unable to look up in source map]\n'