diff --git a/mergeable/plugin/plugin.go b/mergeable/plugin/plugin.go
index d9bf53c..2da5cfc 100644
--- a/mergeable/plugin/plugin.go
+++ b/mergeable/plugin/plugin.go
@@ -229,8 +229,20 @@ func takeAction(ghc githubClient, org, repo string, num int, author string, hasL
 	return nil
 }
 
+func isMergeable(state *string) bool {
+	// returns true if state is nil or empty string
+	if state == nil || *state == "" {
+		return true
+	}
+	lstate := strings.ToLower(*state)
+	if lstate != "has_hooks" && lstate != "clean" && lstate != "unstable" {
+		return false
+	}
+	return true
+}
+
 func takeActionWithContext(ctx context.Context, ghc githubClient, org, repo string, num int, author string, hasLabel, mergeable bool, state *string) error {
-	if state != nil && *state != "" && *state != "HAS_HOOKS" && *state != "CLEAN" && *state != "UNSTABLE" {
+	if !isMergeable(state) {
 		mergeable = false
 	}
 	if !mergeable {
diff --git a/mergeable/plugin/plugin_test.go b/mergeable/plugin/plugin_test.go
index 24544cf..b327bf0 100644
--- a/mergeable/plugin/plugin_test.go
+++ b/mergeable/plugin/plugin_test.go
@@ -655,3 +655,42 @@ func TestCache(t *testing.T) {
 		}
 	}
 }
+
+func Test_isMergeable(t *testing.T) {
+	emptyState := ""
+	blockedState := "BLOCKED"
+	lowerBlockedState := "blocked"
+	tests := []struct {
+		name  string
+		state *string
+		want  bool
+	}{
+		{
+			name:  "nil state",
+			state: nil,
+			want:  true,
+		},
+		{
+			name:  "empty state",
+			state: &emptyState,
+			want:  true,
+		},
+		{
+			name:  "blocked state",
+			state: &blockedState,
+			want:  false,
+		},
+		{
+			name:  "lower blocked state",
+			state: &lowerBlockedState,
+			want:  false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := isMergeable(tt.state); got != tt.want {
+				t.Errorf("isMergeable() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}