diff --git a/models/user/block.go b/models/user/block.go
index 6331b754a39..b636d30a249 100644
--- a/models/user/block.go
+++ b/models/user/block.go
@@ -45,15 +45,20 @@ func UpdateBlockingNote(ctx context.Context, id int64, note string) error {
 }
 
 func IsUserBlockedBy(ctx context.Context, blockee *User, blockerIDs ...int64) bool {
-	if len(blockerIDs) == 0 {
-		return false
-	}
-
 	if blockee.IsAdmin {
 		return false
 	}
 
-	cond := builder.Eq{"user_blocking.blockee_id": blockee.ID}.
+	return HasBlocking(ctx, blockee.ID, blockerIDs...)
+}
+
+// HasBlocking reports whether a blocking relationship exists regardless of the blockee's admin status.
+func HasBlocking(ctx context.Context, blockeeID int64, blockerIDs ...int64) bool {
+	if len(blockerIDs) == 0 {
+		return false
+	}
+
+	cond := builder.Eq{"user_blocking.blockee_id": blockeeID}.
 		And(builder.In("user_blocking.blocker_id", blockerIDs))
 
 	has, _ := db.GetEngine(ctx).Where(cond).Exist(&Blocking{})
diff --git a/services/user/block.go b/services/user/block.go
index 19b4dfa5960..5e82e5c0f13 100644
--- a/services/user/block.go
+++ b/services/user/block.go
@@ -50,7 +50,7 @@ func CanUnblockUser(ctx context.Context, doer, blocker, blockee *user_model.User
 		return false
 	}
 
-	if !user_model.IsUserBlockedBy(ctx, blockee, blocker.ID) {
+	if !user_model.HasBlocking(ctx, blockee.ID, blocker.ID) {
 		return false
 	}
 
diff --git a/services/user/block_test.go b/services/user/block_test.go
index dc90ddd7e2c..f97d19ebf7d 100644
--- a/services/user/block_test.go
+++ b/services/user/block_test.go
@@ -62,4 +62,8 @@ func TestCanUnblockUser(t *testing.T) {
 	assert.True(t, CanUnblockUser(t.Context(), user1, user2, user29))
 	assert.True(t, CanUnblockUser(t.Context(), user2, user2, user29))
 	assert.True(t, CanUnblockUser(t.Context(), user1, org17, user28))
+	// Existing block can still be removed after the blockee becomes an admin.
+	user29.IsAdmin = true
+	assert.False(t, user_model.IsUserBlockedBy(t.Context(), user29, user2.ID))
+	assert.True(t, CanUnblockUser(t.Context(), user2, user2, user29))
 }