diff --git a/.gitignore b/.gitignore
index 3bf3591..a39febb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,5 +17,9 @@ tests/*.xml
 tests/*.txt
 .idea/
 .tox/
+
+# python venv management tools
 Pipfile
-Pipfile.lock
\ No newline at end of file
+Pipfile.lock
+pyproject.toml
+poetry.lock
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a385a89..17b8c6b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Fixed
 - Fix issue of TypeError: cannot unpack non-iterable PDFObjRef object, when unpacking the value of 'DW2' ([#529](https://github.com/pdfminer/pdfminer.six/pull/529))
 - `PermissionError` when creating temporary filepaths on windows when running tests ([#469](https://github.com/pdfminer/pdfminer.six/issues/469))
+- Detecting trailer correctly when surrounded with needless whitespace ([#535](https://github.com/pdfminer/pdfminer.six/pull/535))
 - Fix `.paint_path` logic for handling single line segments and extracting point-on-curve positions of Beziér path commands ([#530](https://github.com/pdfminer/pdfminer.six/pull/530))
 
 ## Removed
diff --git a/pdfminer/pdfdocument.py b/pdfminer/pdfdocument.py
index 108d348..e67eae7 100644
--- a/pdfminer/pdfdocument.py
+++ b/pdfminer/pdfdocument.py
@@ -93,16 +93,15 @@ class PDFXRef(PDFBaseXRef):
         while True:
             try:
                 (pos, line) = parser.nextline()
-                if not line.strip():
+                line = line.strip()
+                if not line:
                     continue
             except PSEOF:
                 raise PDFNoValidXRef('Unexpected EOF - file corrupted?')
-            if not line:
-                raise PDFNoValidXRef('Premature eof: %r' % parser)
             if line.startswith(b'trailer'):
                 parser.seek(pos)
                 break
-            f = line.strip().split(b' ')
+            f = line.split(b' ')
             if len(f) != 2:
                 error_msg = 'Trailer not found: {!r}: line={!r}'\
                     .format(parser, line)
@@ -116,9 +115,10 @@ class PDFXRef(PDFBaseXRef):
             for objid in range(start, start+nobjs):
                 try:
                     (_, line) = parser.nextline()
+                    line = line.strip()
                 except PSEOF:
                     raise PDFNoValidXRef('Unexpected EOF - file corrupted?')
-                f = line.strip().split(b' ')
+                f = line.split(b' ')
                 if len(f) != 3:
                     error_msg = 'Invalid XRef format: {!r}, line={!r}'\
                         .format(parser, line)