diff --git a/addons/report/models/report.py b/addons/report/models/report.py
index 3c7d19fcc3a..36200ce9839 100644
--- a/addons/report/models/report.py
+++ b/addons/report/models/report.py
@@ -560,19 +560,23 @@ class Report(osv.Model):
         """
         writer = PdfFileWriter()
         streams = []  # We have to close the streams *after* PdfFilWriter's call to write()
-        for document in documents:
-            pdfreport = file(document, 'rb')
-            streams.append(pdfreport)
-            reader = PdfFileReader(pdfreport)
-            for page in range(0, reader.getNumPages()):
-                writer.addPage(reader.getPage(page))
+        try:
+            for document in documents:
+                pdfreport = file(document, 'rb')
+                streams.append(pdfreport)
+                reader = PdfFileReader(pdfreport)
+                for page in range(0, reader.getNumPages()):
+                    writer.addPage(reader.getPage(page))
 
-        merged_file_fd, merged_file_path = tempfile.mkstemp(suffix='.html', prefix='report.merged.tmp.')
-        with closing(os.fdopen(merged_file_fd, 'w')) as merged_file:
-            writer.write(merged_file)
-
-        for stream in streams:
-            stream.close()
+            merged_file_fd, merged_file_path = tempfile.mkstemp(suffix='.pdf', prefix='report.merged.tmp.')
+            with closing(os.fdopen(merged_file_fd, 'w')) as merged_file:
+                writer.write(merged_file)
+        finally:
+            for stream in streams:
+                try:
+                    stream.close()
+                except Exception:
+                    pass
 
         return merged_file_path