diff --git a/coverage_comment/settings.py b/coverage_comment/settings.py
index ed0c27c1..5d4360b7 100644
--- a/coverage_comment/settings.py
+++ b/coverage_comment/settings.py
@@ -125,14 +125,14 @@ def clean_github_output(cls, value: str) -> pathlib.Path:
     @property
     def GITHUB_PR_NUMBER(self) -> int | None:
         # "refs/pull/2/merge"
-        if "pull" in self.GITHUB_REF:
+        if self.GITHUB_REF.startswith("refs/pull"):
             return int(self.GITHUB_REF.split("/")[2])
         return None
 
     @property
     def GITHUB_BRANCH_NAME(self) -> str | None:
         # "refs/heads/my_branch_name"
-        if "heads" in self.GITHUB_REF:
+        if self.GITHUB_REF.startswith("refs/heads"):
             return self.GITHUB_REF.split("/", 2)[2]
         return None
 
diff --git a/tests/unit/test_settings.py b/tests/unit/test_settings.py
index a335827f..b283d991 100644
--- a/tests/unit/test_settings.py
+++ b/tests/unit/test_settings.py
@@ -127,6 +127,8 @@ def _(**kwargs):
     "github_ref, github_pr_number",
     [
         ("foo", None),
+        ("refs/heads/branch-with-pull", None),
+        ("refs/tags/tag-with-pull", None),
         ("refs/pull/2/merge", 2),
     ],
 )
@@ -138,6 +140,8 @@ def test_config__GITHUB_PR_NUMBER(config, github_ref, github_pr_number):
     "github_ref, github_branch_name",
     [
         ("refs/pull/2/merge", None),
+        ("refs/pull/2/head", None),
+        ("refs/tags/tag-with-heads", None),
         ("refs/heads/a/b", "a/b"),
     ],
 )