diff --git a/src/sqlancer/postgres/PostgresGlobalState.java b/src/sqlancer/postgres/PostgresGlobalState.java
index 0f2c7ebdb..a5cdceec6 100644
--- a/src/sqlancer/postgres/PostgresGlobalState.java
+++ b/src/sqlancer/postgres/PostgresGlobalState.java
@@ -27,6 +27,7 @@ public class PostgresGlobalState extends SQLGlobalState<PostgresOptions, Postgre
     // store and allow filtering by function volatility classifications
     private final Map<String, Character> functionsAndTypes = new HashMap<>();
     private List<Character> allowedFunctionTypes = Arrays.asList(IMMUTABLE, STABLE, VOLATILE);
+    private int majorVersion;
 
     @Override
     public void setConnection(SQLConnection con) {
@@ -36,6 +37,7 @@ public void setConnection(SQLConnection con) {
             this.operators = getOperators(getConnection());
             this.collates = getCollnames(getConnection());
             this.tableAccessMethods = getTableAccessMethods(getConnection());
+            this.majorVersion = getMajorVersion(getConnection());
         } catch (SQLException e) {
             throw new AssertionError(e);
         }
@@ -93,6 +95,19 @@ private List<String> getTableAccessMethods(SQLConnection con) throws SQLExceptio
         return tableAccessMethods;
     }
 
+    private int getMajorVersion(SQLConnection con) throws SQLException {
+        try (Statement s = con.createStatement()) {
+            try (ResultSet rs = s.executeQuery("SHOW server_version_num;")) {
+                if (rs.next()) {
+                    // Server version returns a number like 130018 for 13.18
+                    // Divide by 10000 to get major version (13)
+                    return rs.getInt(1) / 10000;
+                }
+            }
+        }
+        return 0; // Default to 0 if version cannot be determined
+    }
+
     public List<String> getOperators() {
         return operators;
     }
@@ -150,4 +165,8 @@ public List<Character> getAllowedFunctionTypes() {
         return this.allowedFunctionTypes;
     }
 
+    public int getMajorVersion() {
+        return majorVersion;
+    }
+
 }
diff --git a/src/sqlancer/postgres/gen/PostgresVacuumGenerator.java b/src/sqlancer/postgres/gen/PostgresVacuumGenerator.java
index ef32db45a..67b02f743 100644
--- a/src/sqlancer/postgres/gen/PostgresVacuumGenerator.java
+++ b/src/sqlancer/postgres/gen/PostgresVacuumGenerator.java
@@ -10,6 +10,12 @@
 import sqlancer.postgres.PostgresGlobalState;
 import sqlancer.postgres.PostgresSchema.PostgresTable;
 
+/**
+ * Generates VACUUM commands for PostgreSQL.
+ * This implementation supports PostgreSQL 13 features including the PARALLEL option.
+ * The PARALLEL option specifies the number of parallel worker processes to use when running
+ * a parallel vacuum (only applies to the collection of table data, not indexes).
+ */
 public final class PostgresVacuumGenerator {
 
     private PostgresVacuumGenerator() {
@@ -25,12 +31,27 @@ public static SQLQueryAdapter create(PostgresGlobalState globalState) {
             for (int i = 0; i < Randomly.smallNumber() + 1; i++) {
                 ArrayList<String> opts = new ArrayList<>(Arrays.asList("FULL", "FREEZE", "ANALYZE", "VERBOSE",
                         "DISABLE_PAGE_SKIPPING", "SKIP_LOCKED", "INDEX_CLEANUP", "TRUNCATE"));
+
+                // Add PARALLEL option if PostgreSQL version is 13 or higher
+                int majorVersion = globalState.getMajorVersion();
+                if (majorVersion >= 13) {
+                    opts.add("PARALLEL");
+                }
+                
                 String option = Randomly.fromList(opts);
                 if (i != 0) {
                     sb.append(", ");
                 }
                 sb.append(option);
-                if (Randomly.getBoolean()) {
+                
+                // For PostgreSQL v13+, PARALLEL always needs a value
+                if (option.equals("PARALLEL") && majorVersion >= 13) {
+                    // PARALLEL takes integer value between 0 and 1024
+                    sb.append(" ");
+                    sb.append(Randomly.getNotCachedInteger(0, 4)); // Use reasonable value for testing
+                } 
+                // For other options, randomly decide whether to append a value
+                else if (Randomly.getBoolean()) {
                     sb.append(" ");
                     sb.append(Randomly.fromOptions(1, 0));
                 }
@@ -60,6 +81,12 @@ public static SQLQueryAdapter create(PostgresGlobalState globalState) {
                                  */
         errors.add("ERROR: ANALYZE option must be specified when a column list is provided");
         errors.add("VACUUM option DISABLE_PAGE_SKIPPING cannot be used with FULL");
+        
+        // Add error specific to PostgreSQL v13's PARALLEL option
+        if (globalState.getMajorVersion() >= 13) {
+            errors.add("VACUUM option PARALLEL cannot be used with FULL");
+        }
+        
         return new SQLQueryAdapter(sb.toString(), errors);
     }