diff --git a/pkg/engine/pattern.go b/pkg/engine/pattern.go
index 56929a692d..c7d20ba650 100644
--- a/pkg/engine/pattern.go
+++ b/pkg/engine/pattern.go
@@ -240,6 +240,10 @@ func validateNumber(value, pattern interface{}, operator Operator) bool {
 }
 
 func getOperatorFromStringPattern(pattern string) Operator {
+	if len(pattern) < 2 {
+		return Equal
+	}
+
 	if pattern[:len(MoreEqual)] == string(MoreEqual) {
 		return MoreEqual
 	}
@@ -260,7 +264,7 @@ func getOperatorFromStringPattern(pattern string) Operator {
 		return NotEqual
 	}
 
-	return ""
+	return Equal
 }
 
 func getNumberAndStringPartsFromPattern(pattern string) (number, str string) {
diff --git a/pkg/engine/pattern_test.go b/pkg/engine/pattern_test.go
index b61c0d2a4e..2ce21ddde2 100644
--- a/pkg/engine/pattern_test.go
+++ b/pkg/engine/pattern_test.go
@@ -269,3 +269,15 @@ func TestValidateNumberWithStr_MoreAndWildCard(t *testing.T) {
 func TestValidateNumberWithStr_NoStr(t *testing.T) {
 	assert.Assert(t, validateNumberWithStr(2048, "1024", "", More))
 }
+
+func TestGetOperatorFromStringPattern_OneChar(t *testing.T) {
+	assert.Equal(t, getOperatorFromStringPattern("f"), Equal)
+}
+
+func TestGetOperatorFromStringPattern_EmptyString(t *testing.T) {
+	assert.Equal(t, getOperatorFromStringPattern(""), Equal)
+}
+
+func TestGetOperatorFromStringPattern_OnlyOperator(t *testing.T) {
+	assert.Equal(t, getOperatorFromStringPattern(">="), MoreEqual)
+}