diff --git a/include/git2/odb.h b/include/git2/odb.h
index b64436c4d..b3e9a57a6 100644
--- a/include/git2/odb.h
+++ b/include/git2/odb.h
@@ -120,7 +120,7 @@ GIT_EXTERN(int) git_odb_read(git_odb_object **out, git_odb *db, const git_oid *i
  * @param db database to search for the object in.
  * @param short_id a prefix of the id of the object to read.
  * @param len the length of the prefix
- * @return 
+ * @return
  * - 0 if the object was read;
  * - GIT_ENOTFOUND if the object is not in the database.
  * - GIT_EAMBIGUOUS if the prefix is ambiguous (several objects match the prefix)
diff --git a/tests-clar/odb/mixed.c b/tests-clar/odb/mixed.c
index da0ed97d7..7f7120a6e 100644
--- a/tests-clar/odb/mixed.c
+++ b/tests-clar/odb/mixed.c
@@ -18,8 +18,72 @@ void test_odb_mixed__dup_oid(void) {
 	const char hex[] = "ce013625030ba8dba906f756967f9e9ca394464a";
 	git_oid oid;
 	git_odb_object *obj;
+
 	cl_git_pass(git_oid_fromstr(&oid, hex));
 	cl_git_pass(git_odb_read_prefix(&obj, _odb, &oid, GIT_OID_HEXSZ));
 	git_odb_object_free(obj);
 }
 
+/* some known sha collisions of file content:
+ *   'aabqhq' and 'aaazvc' with prefix 'dea509d0' (+ '9' and + 'b')
+ *   'aaeufo' and 'aaaohs' with prefix '81b5bff5' (+ 'f' and + 'b')
+ *   'aafewy' and 'aaepta' with prefix '739e3c4c'
+ *   'aahsyn' and 'aadrjg' with prefix '0ddeaded' (+ '9' and + 'e')
+ */
+
+void test_odb_mixed__dup_oid_prefix_0(void) {
+	char hex[10];
+	git_oid oid;
+	git_odb_object *obj;
+
+	/* ambiguous in the same pack file */
+
+	strncpy(hex, "dea509d0", sizeof(hex));
+	cl_git_pass(git_oid_fromstrn(&oid, hex, strlen(hex)));
+	cl_assert_equal_i(
+		GIT_EAMBIGUOUS, git_odb_read_prefix(&obj, _odb, &oid, strlen(hex)));
+
+	strncpy(hex, "dea509d09", sizeof(hex));
+	cl_git_pass(git_oid_fromstrn(&oid, hex, strlen(hex)));
+	cl_git_pass(git_odb_read_prefix(&obj, _odb, &oid, strlen(hex)));
+	git_odb_object_free(obj);
+
+	strncpy(hex, "dea509d0b", sizeof(hex));
+	cl_git_pass(git_oid_fromstrn(&oid, hex, strlen(hex)));
+	cl_git_pass(git_odb_read_prefix(&obj, _odb, &oid, strlen(hex)));
+	git_odb_object_free(obj);
+
+	/* ambiguous in different pack files */
+
+	strncpy(hex, "81b5bff5", sizeof(hex));
+	cl_git_pass(git_oid_fromstrn(&oid, hex, strlen(hex)));
+	cl_assert_equal_i(
+		GIT_EAMBIGUOUS, git_odb_read_prefix(&obj, _odb, &oid, strlen(hex)));
+
+	strncpy(hex, "81b5bff5b", sizeof(hex));
+	cl_git_pass(git_oid_fromstrn(&oid, hex, strlen(hex)));
+	cl_git_pass(git_odb_read_prefix(&obj, _odb, &oid, strlen(hex)));
+	git_odb_object_free(obj);
+
+	strncpy(hex, "81b5bff5f", sizeof(hex));
+	cl_git_pass(git_oid_fromstrn(&oid, hex, strlen(hex)));
+	cl_git_pass(git_odb_read_prefix(&obj, _odb, &oid, strlen(hex)));
+	git_odb_object_free(obj);
+
+	/* ambiguous in pack file and loose */
+
+	strncpy(hex, "0ddeaded", sizeof(hex));
+	cl_git_pass(git_oid_fromstrn(&oid, hex, strlen(hex)));
+	cl_assert_equal_i(
+		GIT_EAMBIGUOUS, git_odb_read_prefix(&obj, _odb, &oid, strlen(hex)));
+
+	strncpy(hex, "0ddeaded9", sizeof(hex));
+	cl_git_pass(git_oid_fromstrn(&oid, hex, strlen(hex)));
+	cl_git_pass(git_odb_read_prefix(&obj, _odb, &oid, strlen(hex)));
+	git_odb_object_free(obj);
+
+	strncpy(hex, "0ddeadede", sizeof(hex));
+	cl_git_pass(git_oid_fromstrn(&oid, hex, strlen(hex)));
+	cl_git_pass(git_odb_read_prefix(&obj, _odb, &oid, strlen(hex)));
+	git_odb_object_free(obj);
+}
diff --git a/tests-clar/resources/duplicate.git/config b/tests-clar/resources/duplicate.git/config
index 515f48362..a4ef456cb 100644
--- a/tests-clar/resources/duplicate.git/config
+++ b/tests-clar/resources/duplicate.git/config
@@ -1,5 +1,5 @@
 [core]
 	repositoryformatversion = 0
 	filemode = true
-	bare = false
+	bare = true
 	logallrefupdates = true
diff --git a/tests-clar/resources/duplicate.git/objects/0d/deadede9e6d6ccddce0ee1e5749eed0485e5ea b/tests-clar/resources/duplicate.git/objects/0d/deadede9e6d6ccddce0ee1e5749eed0485e5ea
new file mode 100644
index 000000000..47c2a631a
Binary files /dev/null and b/tests-clar/resources/duplicate.git/objects/0d/deadede9e6d6ccddce0ee1e5749eed0485e5ea differ
diff --git a/tests-clar/resources/duplicate.git/objects/pack/pack-29a4896f0a0b9c9947b0927c57a5c03dcae052e3.idx b/tests-clar/resources/duplicate.git/objects/pack/pack-29a4896f0a0b9c9947b0927c57a5c03dcae052e3.idx
new file mode 100644
index 000000000..acbed82b6
Binary files /dev/null and b/tests-clar/resources/duplicate.git/objects/pack/pack-29a4896f0a0b9c9947b0927c57a5c03dcae052e3.idx differ
diff --git a/tests-clar/resources/duplicate.git/objects/pack/pack-29a4896f0a0b9c9947b0927c57a5c03dcae052e3.pack b/tests-clar/resources/duplicate.git/objects/pack/pack-29a4896f0a0b9c9947b0927c57a5c03dcae052e3.pack
new file mode 100644
index 000000000..652b0c91f
Binary files /dev/null and b/tests-clar/resources/duplicate.git/objects/pack/pack-29a4896f0a0b9c9947b0927c57a5c03dcae052e3.pack differ
diff --git a/tests-clar/resources/duplicate.git/objects/pack/pack-b18eeacbd65cbd30a365d7564b45a468e8bd43d6.idx b/tests-clar/resources/duplicate.git/objects/pack/pack-b18eeacbd65cbd30a365d7564b45a468e8bd43d6.idx
new file mode 100644
index 000000000..fff685554
Binary files /dev/null and b/tests-clar/resources/duplicate.git/objects/pack/pack-b18eeacbd65cbd30a365d7564b45a468e8bd43d6.idx differ
diff --git a/tests-clar/resources/duplicate.git/objects/pack/pack-b18eeacbd65cbd30a365d7564b45a468e8bd43d6.pack b/tests-clar/resources/duplicate.git/objects/pack/pack-b18eeacbd65cbd30a365d7564b45a468e8bd43d6.pack
new file mode 100644
index 000000000..e3e5f0e09
Binary files /dev/null and b/tests-clar/resources/duplicate.git/objects/pack/pack-b18eeacbd65cbd30a365d7564b45a468e8bd43d6.pack differ
diff --git a/tests-clar/resources/duplicate.git/refs/heads/dummy-marker.txt b/tests-clar/resources/duplicate.git/refs/heads/dummy-marker.txt
new file mode 100644
index 000000000..421376db9
--- /dev/null
+++ b/tests-clar/resources/duplicate.git/refs/heads/dummy-marker.txt
@@ -0,0 +1 @@
+dummy