diff --git a/query/query.go b/query/query.go
index c0de41a..7cbf9a2 100644
--- a/query/query.go
+++ b/query/query.go
@@ -785,7 +785,7 @@ func Fingerprint(q string) string {
 				addSpace = false
 				// since we only consider the keywords if it exists at a top-level (except onDupeKeyUpdate),
 				// we only do the conversion below if the "keywords" actually open a value list (i.e., before opening a parenthesis).
-				if r == '(' || (isSpace(r) && (q[qi+1] == '(') || (q[qi+1] == ' ')) {
+				if r == '(' || (isSpace(r) && qi+1 < len(q) && ((q[qi+1] == '(') || (q[qi+1] == ' '))) {
 					// IN ()     -> in(?+)
 					// VALUES () -> values(?+)
 					s = inValues
diff --git a/query/query_test.go b/query/query_test.go
index 389a0b9..427854b 100644
--- a/query/query_test.go
+++ b/query/query_test.go
@@ -693,3 +693,25 @@ func TestFingerprintSubqueries(t *testing.T) {
 		})
 	}
 }
+
+func TestFingerprintSystemVariableQueries(t *testing.T) {
+	type testCase struct {
+		name     string
+		query    string
+		expected string
+	}
+	// Test cases for system variable queries
+	testCases := []testCase{
+		{
+			name:     "global read_only",
+			query:    "set long_query_time = 0; SELECT @@GLOBAL.read_only AS Value",
+			expected: "set long_query_time = ?; select @@global.read_only as value",
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			actual := query.Fingerprint(tc.query)
+			assert.Equal(t, tc.expected, actual, "Query: %s", tc.query)
+		})
+	}
+}