diff --git a/pkg/client/util.go b/pkg/client/util.go
index b7a7fb4e8..d32313fd0 100644
--- a/pkg/client/util.go
+++ b/pkg/client/util.go
@@ -8,7 +8,8 @@ import (
 
 var (
 	// List of keywords that are not allowed in read-only mode
-	reRestrictedKeywords = regexp.MustCompile(`(?mi)\s?(CREATE|INSERT|UPDATE|DROP|DELETE|TRUNCATE|GRANT|OPEN|IMPORT|COPY)\s`)
+	reRestrictedKeywords  = regexp.MustCompile(`(?mi)\s?(CREATE|INSERT|UPDATE|DROP|DELETE|TRUNCATE|GRANT|OPEN|IMPORT|COPY)\s`)
+	reRestrictedFunctions = regexp.MustCompile(`(?mi)(pg_cancel_backend|pg_terminate_backend)\s*\(`)
 
 	// Comment regular expressions
 	reSlashComment = regexp.MustCompile(`(?m)/\*.+\*/`)
@@ -85,7 +86,7 @@ func containsRestrictedKeywords(str string) bool {
 	str = reSlashComment.ReplaceAllString(str, "")
 	str = reDashComment.ReplaceAllString(str, "")
 
-	return reRestrictedKeywords.MatchString(str)
+	return reRestrictedKeywords.MatchString(str) || reRestrictedFunctions.MatchString(str)
 }
 
 func hasBinary(data string, checkLen int) bool {
diff --git a/pkg/client/util_test.go b/pkg/client/util_test.go
index 2551d87a1..8a46b1ac8 100644
--- a/pkg/client/util_test.go
+++ b/pkg/client/util_test.go
@@ -95,6 +95,32 @@ func TestGetMajorMinorVersion(t *testing.T) {
 	}
 }
 
+func TestContainsRestrictedKeywords(t *testing.T) {
+	examples := []struct {
+		input  string
+		result bool
+	}{
+		{"SELECT 1", false},
+		{"SELECT * FROM users", false},
+		{"CREATE TABLE foo (id int)", true},
+		{"INSERT INTO foo VALUES (1)", true},
+		{"DROP TABLE foo", true},
+		{"DELETE FROM foo", true},
+		{"SELECT pg_cancel_backend(1234)", true},
+		{"SELECT pg_terminate_backend(1234)", true},
+		{"select pg_cancel_backend( 1234 )", true},
+		{"select pg_terminate_backend( 1234 )", true},
+		{"SELECT PG_CANCEL_BACKEND(1234)", true},
+		{"SELECT PG_TERMINATE_BACKEND(1234)", true},
+	}
+
+	for _, ex := range examples {
+		t.Run(ex.input, func(t *testing.T) {
+			assert.Equal(t, ex.result, containsRestrictedKeywords(ex.input))
+		})
+	}
+}
+
 func TestCheckVersionRequirement(t *testing.T) {
 	examples := []struct {
 		client string