diff --git a/phpunit/code/bigint-post-inc.php b/phpunit/code/bigint-post-inc.php
new file mode 100644
index 00000000..708ccfbf
--- /dev/null
+++ b/phpunit/code/bigint-post-inc.php
@@ -0,0 +1,8 @@
+<?php
+declare(strict_types=1);
+use native_types;
+function main()
+{
+    $a = std::bigInt(100);
+    $a++;
+}
diff --git a/phpunit/code/bigint-pre-inc.php b/phpunit/code/bigint-pre-inc.php
new file mode 100644
index 00000000..e67ab615
--- /dev/null
+++ b/phpunit/code/bigint-pre-inc.php
@@ -0,0 +1,8 @@
+<?php
+declare(strict_types=1);
+use native_types;
+function main()
+{
+    $a = std::bigInt(100);
+    ++$a;
+}
diff --git a/phpunit/code/decimal-pre-dec.php b/phpunit/code/decimal-pre-dec.php
new file mode 100644
index 00000000..3c8aa589
--- /dev/null
+++ b/phpunit/code/decimal-pre-dec.php
@@ -0,0 +1,8 @@
+<?php
+declare(strict_types=1);
+use native_types;
+function main()
+{
+    $a = std::decimal("100");
+    --$a;
+}
diff --git a/phpunit/src/AssignOpTest.php b/phpunit/src/AssignOpTest.php
index c0e37587..4aa1c8db 100644
--- a/phpunit/src/AssignOpTest.php
+++ b/phpunit/src/AssignOpTest.php
@@ -11,4 +11,19 @@ class AssignOpTest extends \BaseTest
     {
         $this->exec('Cannot concat string to array', 'assign-op-concat-array.php');
     }
+
+    public function testBigIntPreInc()
+    {
+        $this->exec('Cannot use ++ on php::BigInt', 'bigint-pre-inc.php');
+    }
+
+    public function testBigIntPostInc()
+    {
+        $this->exec('Cannot use ++ on php::BigInt', 'bigint-post-inc.php');
+    }
+
+    public function testDecimalPreDec()
+    {
+        $this->exec('Cannot use -- on php::Decimal', 'decimal-pre-dec.php');
+    }
 }
diff --git a/src/Php/CompilerBase.php b/src/Php/CompilerBase.php
index ed41ac20..59bc8342 100644
--- a/src/Php/CompilerBase.php
+++ b/src/Php/CompilerBase.php
@@ -3018,6 +3018,10 @@ class CompilerBase extends \PhpAot\Core\Translator
 
     protected function parsePreInc(Expr\PreInc $expr): string
     {
+        $type = $this->detectVarType($expr->var);
+        if ($type === self::TYPE_BIGINT || $type === self::TYPE_DECIMAL || $type === self::TYPE_BIGFLOAT) {
+            $this->fatalError($expr, 'Cannot use ++ on ' . $type . '. Use += 1 instead (Big* types are immutable).');
+        }
         return '++' . $this->parseIdentifier($expr->var);
     }
 
@@ -3721,6 +3725,11 @@ class CompilerBase extends \PhpAot\Core\Translator
             if ($this->isVarExpr($expr->var) and !$this->hasVar($var)) {
                 $this->errorUndefinedVariable($expr->var);
             }
+            $type = $this->detectVarType($expr->var);
+            if ($type === self::TYPE_BIGINT || $type === self::TYPE_DECIMAL || $type === self::TYPE_BIGFLOAT) {
+                $opName = $op === '+' ? '++' : '--';
+                $this->fatalError($expr, "Cannot use {$opName} on {$type}. Use " . ($op === '+' ? '+= 1' : '-= 1') . ' instead (Big* types are immutable).');
+            }
             return $var . str_repeat($op, 2);
         }
         if ($this->isStaticPropertyFetch($expr->var)) {
@@ -3828,6 +3837,10 @@ class CompilerBase extends \PhpAot\Core\Translator
 
     protected function parsePreDec(Expr\PreDec $expr): string
     {
+        $type = $this->detectVarType($expr->var);
+        if ($type === self::TYPE_BIGINT || $type === self::TYPE_DECIMAL || $type === self::TYPE_BIGFLOAT) {
+            $this->fatalError($expr, 'Cannot use -- on ' . $type . '. Use -= 1 instead (Big* types are immutable).');
+        }
         return '--' . $this->parseIdentifier($expr->var);
     }
 
diff --git a/tests/aot/bigint/assign_op.phpt b/tests/aot/bigint/assign_op.phpt
new file mode 100644
index 00000000..1212d2b5
--- /dev/null
+++ b/tests/aot/bigint/assign_op.phpt
@@ -0,0 +1,46 @@
+--TEST--
+BigInt compound assignment operators (+=, -=, *=, /=, %=)
+--FILE--
+<?php
+declare(strict_types=1);
+use native_types;
+
+function main(): void {
+    // BigInt +=
+    $a = std::bigInt(100);
+    $a += 50;
+    echo $a->toString(); echo "\n";
+
+    // BigInt += with BigInt
+    $b = std::bigInt("99999999999999999999");
+    $b += std::bigInt(1);
+    echo $b->toString(); echo "\n";
+
+    // BigInt -=
+    $c = std::bigInt(1000);
+    $c -= 300;
+    echo $c->toString(); echo "\n";
+
+    // BigInt *=
+    $d = std::bigInt(100);
+    $d *= 5;
+    echo $d->toString(); echo "\n";
+
+    // BigInt /=
+    $e = std::bigInt(100);
+    $e /= 3;
+    echo $e->toString(); echo "\n";
+
+    // BigInt %=
+    $f = std::bigInt(100);
+    $f %= 7;
+    echo $f->toString(); echo "\n";
+}
+?>
+--EXPECT--
+150
+100000000000000000000
+700
+500
+33
+2
diff --git a/tests/aot/bigint/operator.phpt b/tests/aot/bigint/operator.phpt
new file mode 100644
index 00000000..5645657c
--- /dev/null
+++ b/tests/aot/bigint/operator.phpt
@@ -0,0 +1,49 @@
+--TEST--
+BigInt binary operators (+, -, *, /, %) and unary minus
+--FILE--
+<?php
+declare(strict_types=1);
+use native_types;
+
+function main(): void {
+    $a = std::bigInt(100);
+
+    // BigInt + Int
+    $b = $a + 50;
+    echo $b->toString(); echo "\n";
+    // Int + BigInt
+    $c = 200 + $a;
+    echo $c->toString(); echo "\n";
+    // BigInt - Int
+    $d = $a - 30;
+    echo $d->toString(); echo "\n";
+    // BigInt * Int
+    $e = $a * 5;
+    echo $e->toString(); echo "\n";
+    // BigInt / Int
+    $f = $a / 3;
+    echo $f->toString(); echo "\n";
+    // BigInt % Int
+    $g = $a % 7;
+    echo $g->toString(); echo "\n";
+
+    // BigInt ** Int
+    $h = std::bigInt(2) ** 10;
+    echo $h->toString(); echo "\n";
+
+    // Unary minus
+    $i = -$a;
+    echo $i->toString(); echo "\n";
+    echo (-$i)->toString(); echo "\n";
+}
+?>
+--EXPECT--
+150
+300
+70
+500
+33
+2
+1024
+-100
+100
diff --git a/tests/aot/decimal/arithmetic.phpt b/tests/aot/decimal/arithmetic.phpt
new file mode 100644
index 00000000..284993c5
--- /dev/null
+++ b/tests/aot/decimal/arithmetic.phpt
@@ -0,0 +1,36 @@
+--TEST--
+Decimal arithmetic operations
+--FILE--
+<?php
+declare(strict_types=1);
+use native_types;
+
+function main(): void {
+    $a = std::decimal("100.50");
+    $b = std::decimal("50.25");
+
+    // Decimal + Decimal
+    echo $a->add($b)->toString(); echo "\n";
+    // Decimal - Decimal
+    echo $a->sub($b)->toString(); echo "\n";
+    // Decimal * Decimal
+    echo $a->mul($b)->toString(); echo "\n";
+    // Decimal / Decimal
+    echo $a->div($b)->toString(); echo "\n";
+    // Decimal mod
+    $c = std::decimal("17.5");
+    echo $c->mod(std::decimal("5.0"))->toString(); echo "\n";
+    // Decimal neg
+    echo $a->neg()->toString(); echo "\n";
+    // Decimal abs
+    echo $a->neg()->abs()->toString(); echo "\n";
+}
+?>
+--EXPECT--
+150.75
+50.25
+5050.1250
+2
+2.5
+-100.50
+100.50
diff --git a/tests/aot/decimal/assign_op.phpt b/tests/aot/decimal/assign_op.phpt
new file mode 100644
index 00000000..2a446097
--- /dev/null
+++ b/tests/aot/decimal/assign_op.phpt
@@ -0,0 +1,45 @@
+--TEST--
+Decimal compound assignment operators (+=, -=, *=, /=, %=)
+--FILE--
+<?php
+declare(strict_types=1);
+use native_types;
+
+function main(): void {
+    // Decimal +=
+    $a = std::decimal("100.50");
+    $a += 25.25;
+    echo $a->toString(); echo "\n";
+
+    // Decimal += with int
+    $a += 100;
+    echo $a->toString(); echo "\n";
+
+    // Decimal -=
+    $b = std::decimal("500.00");
+    $b -= 123.45;
+    echo $b->toString(); echo "\n";
+
+    // Decimal *=
+    $c = std::decimal("50.5");
+    $c *= 2;
+    echo $c->toString(); echo "\n";
+
+    // Decimal /=
+    $d = std::decimal("100.00");
+    $d /= 4;
+    echo $d->toString(); echo "\n";
+
+    // Decimal %=
+    $e = std::decimal("17.5");
+    $e %= 5.0;
+    echo $e->toString(); echo "\n";
+}
+?>
+--EXPECT--
+125.75
+225.75
+376.55
+101.0
+25.00
+2.5
diff --git a/tests/aot/decimal/compare.phpt b/tests/aot/decimal/compare.phpt
new file mode 100644
index 00000000..1b348c20
--- /dev/null
+++ b/tests/aot/decimal/compare.phpt
@@ -0,0 +1,26 @@
+--TEST--
+Decimal comparison and conversions
+--FILE--
+<?php
+declare(strict_types=1);
+use native_types;
+
+function main(): void {
+    $a = std::decimal("123.456");
+    $b = std::decimal("789.012");
+
+    echo "cmp(a,b)="; echo $a->cmp($b); echo "\n";
+    echo "cmp(b,a)="; echo $b->cmp($a); echo "\n";
+    echo "cmp(a,a)="; echo $a->cmp($a); echo "\n";
+
+    // conversion
+    echo $a->toInt(); echo "\n";
+    echo $a->toString(); echo "\n";
+}
+?>
+--EXPECT--
+cmp(a,b)=-1
+cmp(b,a)=1
+cmp(a,a)=0
+123
+123.456
diff --git a/tests/aot/decimal/operator.phpt b/tests/aot/decimal/operator.phpt
new file mode 100644
index 00000000..407d5359
--- /dev/null
+++ b/tests/aot/decimal/operator.phpt
@@ -0,0 +1,51 @@
+--TEST--
+Decimal operator overloading (+, -, *, /, %) and comparisons
+--FILE--
+<?php
+declare(strict_types=1);
+use native_types;
+
+function main(): void {
+    $dec = std::decimal("100.25");
+
+    // Decimal + Int
+    $a = $dec + 50;
+    echo $a->toString(); echo "\n";
+    // Int + Decimal
+    $b = 200 + $dec;
+    echo $b->toString(); echo "\n";
+    // Decimal - Float
+    $c = $dec - 0.25;
+    echo $c->toString(); echo "\n";
+    // Decimal * Int
+    $d = $dec * 4;
+    echo $d->toString(); echo "\n";
+    // Decimal / Int
+    $e = $dec / 5;
+    echo $e->toString(); echo "\n";
+    // Decimal % Int
+    $f = $dec % 7;
+    echo $f->toString(); echo "\n";
+
+    // Comparisons
+    echo (int)($dec > 50); echo "\n";
+    echo (int)($dec < 200); echo "\n";
+    echo (int)($dec == 100.25); echo "\n";
+    echo (int)($dec != 100); echo "\n";
+    echo (int)($dec <= 100.25); echo "\n";
+    echo (int)($dec >= 100); echo "\n";
+}
+?>
+--EXPECT--
+150.25
+300.25
+100.00
+401.00
+20.05
+2.25
+1
+1
+1
+1
+1
+1
diff --git a/tests/aot/decimal/unary_minus.phpt b/tests/aot/decimal/unary_minus.phpt
new file mode 100644
index 00000000..903b5fb3
--- /dev/null
+++ b/tests/aot/decimal/unary_minus.phpt
@@ -0,0 +1,21 @@
+--TEST--
+Decimal unary minus operator
+--FILE--
+<?php
+declare(strict_types=1);
+use native_types;
+
+function main(): void {
+    $a = std::decimal("123.456");
+
+    // Unary minus
+    $b = -$a;
+    echo $b->toString(); echo "\n";
+    // Double minus
+    $c = -$b;
+    echo $c->toString(); echo "\n";
+}
+?>
+--EXPECT--
+-123.456
+123.456