diff --git a/src/slider/slide.py b/src/slider/slide.py
index 89d2196056d2f30a737c7f802f2229aa90920504..1dfc8b09a08d95c849c038a1a6a301a78b91371a 100644
--- a/src/slider/slide.py
+++ b/src/slider/slide.py
@@ -248,17 +248,26 @@ def _do_slide_conversion(MAIN_TEX_DIR, d, fix_broken_osvg_files, verbose):
 
 
 def slide_no_by_text(pdf_file, text):
-    assert False
+    # assert False
     # Make .png background images.
+    from PyPDF2 import PdfReader
+
+    # reader = PdfReader("example.pdf")
+    # number_of_pages = len(reader.pages)
+
     if os.path.exists(pdf_file):
-        with open(pdf_file, 'rb') as f:
-            print(pdf_file)
-            pdfdoc = PyPDF2.PdfReader(f)
-            for i in range(len(pdfdoc.pages)):
-                content = pdfdoc.pages[i].extract_text()
-                # for j, d in enumerate(sinfo):
-                if text in content:
-                    return i+1
+        from PyPDF2 import PdfReader
+
+        reader = PdfReader(pdf_file)
+
+        # with open(pdf_file, 'rb') as f:
+        #     print(pdf_file)
+        #     pdfdoc = PyPDF2.PdfReader(f)
+        for i in range(len(reader.pages)):
+            content = reader.pages[i].extract_text()
+            # for j, d in enumerate(sinfo):
+            if text in content:
+                return i+1
     else:
         print("Warning: slide.py() -> slide_no_by_text(): PDF file not found " + pdf_file)
     return -1