diff --git a/semanticscholar/AsyncSemanticScholar.py b/semanticscholar/AsyncSemanticScholar.py
index cce4eb7..9170bb3 100644
--- a/semanticscholar/AsyncSemanticScholar.py
+++ b/semanticscholar/AsyncSemanticScholar.py
@@ -228,6 +228,7 @@ def _get_not_found_ids(self, paper_ids, papers):
 
         prefix_mapping = {
             'ARXIV': 'ArXiv',
+            'DOI': 'DOI',
             'MAG': 'MAG',
             'ACL': 'ACL',
             'PMID': 'PubMed',
@@ -241,11 +242,10 @@ def _get_not_found_ids(self, paper_ids, papers):
             found_ids.add(paper.paperId)
             if paper.externalIds:
                 for prefix, value in paper.externalIds.items():
+                    found_ids.add(f'{value}')
                     if prefix.lower() in prefix_mapping:
                         found_ids.add(
                             f'{prefix_mapping[prefix.lower()]}:{value}')
-                    else:
-                        found_ids.add(f'{value}')
         found_ids = {id.lower() for id in found_ids}
 
         not_found_ids = [id for id in paper_ids if id.lower() not in found_ids]
diff --git a/tests/test_semanticscholar.py b/tests/test_semanticscholar.py
index 55ad8e2..8bc9183 100644
--- a/tests/test_semanticscholar.py
+++ b/tests/test_semanticscholar.py
@@ -284,6 +284,18 @@ def test_get_papers_return_not_found(self):
         self.assertEqual(len(not_found), 1)
         self.assertEqual(not_found[0], 'CorpusId:211530585')
 
+    def test_get_papers_doi_prefix_not_false_positive(self):
+        paper = Paper({
+            'paperId': 'abc123',
+            'externalIds': {
+                'DOI': '10.1145/792550.792552',
+                'CorpusId': 12345
+            }
+        })
+        not_found = self.sch._AsyncSemanticScholar._get_not_found_ids(
+            ['DOI:10.1145/792550.792552'], [paper])
+        self.assertEqual(not_found, [])
+
     @test_vcr.use_cassette
     def test_get_paper_authors(self):
         data = self.sch.get_paper_authors('10.2139/ssrn.2250500')
@@ -829,7 +841,19 @@ async def test_get_papers_return_not_found_async(self):
         not_found = data[1]
         self.assertEqual(len(not_found), 1)
         self.assertEqual(not_found[0], 'CorpusId:211530585')
-    
+
+    def test_get_papers_doi_prefix_not_false_positive_async(self):
+        paper = Paper({
+            'paperId': 'abc123',
+            'externalIds': {
+                'DOI': '10.1145/792550.792552',
+                'CorpusId': 12345
+            }
+        })
+        not_found = self.sch._get_not_found_ids(
+            ['DOI:10.1145/792550.792552'], [paper])
+        self.assertEqual(not_found, [])
+
     @test_vcr.use_cassette
     async def test_get_paper_authors_async(self):
         data = await self.sch.get_paper_authors('10.2139/ssrn.2250500')