diff --git a/lib/Compiler.php b/lib/Compiler.php
index 7be1de26a85..17ad072e481 100644
--- a/lib/Compiler.php
+++ b/lib/Compiler.php
@@ -4042,7 +4042,7 @@ private function compileEchoWithEmbeddedCoalesce(Op $op, Block $block, array $op
                 }
                 $parts[] = $replaced;
             }
-            $concat = new Op\Expr\ConcatList($parts);
+            $concat = new Op\Expr\ConcatList($parts, $flattened->getAttributes());
             $concat->result = $flattened->result;
             $this->compileOp($concat, $block);
             $var = $this->compileOperand($concat->result, $block, true);
@@ -5495,7 +5495,7 @@ private function flattenBinaryConcatFromBlockOps(array $ops, int $echoIndex, Ope
             return null;
         }
         $parts = array_reverse($parts);
-        $list = new Op\Expr\ConcatList($parts);
+        $list = new Op\Expr\ConcatList($parts, $outer->getAttributes());
         $list->result = $outer->result;
 
         return $list;
@@ -5528,7 +5528,7 @@ private function flattenBinaryConcatToConcatList(?Operand $operand): ?Op\Expr\Co
             return null;
         }
         $parts = array_reverse($parts);
-        $list = new Op\Expr\ConcatList($parts);
+        $list = new Op\Expr\ConcatList($parts, $topConcat->getAttributes());
         $list->result = $topConcat->result;
 
         return $list;
@@ -5763,15 +5763,17 @@ private function materializeConcatListCoalesceParts(Op\Expr\ConcatList $concat,
             $readSlot = $this->compileOperand($part, $block, true);
             $fresh = new Operand\Temporary();
             $writeSlot = $block->forceFreshVarSlot($fresh);
-            $block->addOpCode(new OpCode(
+            $assignOp = new OpCode(
                 OpCode::TYPE_ASSIGN,
                 $writeSlot,
                 $writeSlot,
                 $readSlot
-            ));
+            );
+            $this->assignConcatListSourceMetadata($assignOp, $concat);
+            $block->addOpCode($assignOp);
             $parts[] = $fresh;
         }
-        $materialized = new Op\Expr\ConcatList($parts);
+        $materialized = new Op\Expr\ConcatList($parts, $concat->getAttributes());
         $materialized->result = $concat->result;
 
         return $materialized;
@@ -5826,6 +5828,54 @@ private function compileConcatListPart(Operand $part, Block $block): int
         return $this->compileOperand($part, $block, true);
     }
 
+    /**
+     * CONCAT/CAST_STRING from encapsed ConcatList must carry the user site so
+     * Undefined variable warnings do not inherit the prior statement's opline (#32034).
+     *
+     * php-src: Zend/zend_compile.c zend_compile_encapsed_string — FETCH_R lineno is the
+     * interpolated expression, not the previous statement.
+     */
+    private function addConcatListOpCode(Block $block, OpCode $opcode, Op\Expr\ConcatList $concat): void
+    {
+        $this->assignConcatListSourceMetadata($opcode, $concat);
+        $block->addOpCode($opcode);
+    }
+
+    private function assignConcatListSourceMetadata(OpCode $opcode, Op\Expr\ConcatList $concat): void
+    {
+        $this->assignSourceMetadata($opcode, $concat);
+        $line = $this->concatListWarningLine($concat);
+        if ($line <= 0) {
+            return;
+        }
+        $loc = $opcode->sourceLocation;
+        if (null !== $loc && $loc->startLine === $line) {
+            return;
+        }
+        $opcode->sourceLocation = new SourceLocation(
+            $loc?->docComment,
+            $line,
+            $loc?->endLine ?? max(0, (int) $concat->getAttribute('endLine', 0)),
+            $loc?->filename ?? (string) $concat->getAttribute('filename', '')
+        );
+    }
+
+    /**
+     * Heredoc ConcatList startLine is the `<<<LABEL` opener; Zend FETCH_R cites the body
+     * (php-parser String_::KIND_HEREDOC === 3, #32034).
+     */
+    private function concatListWarningLine(Op\Expr\ConcatList $concat): int
+    {
+        $start = max(0, $concat->getLine());
+        $end = max(0, (int) $concat->getAttribute('endLine', 0));
+        $kind = (int) $concat->getAttribute('kind', 0);
+        if (3 === $kind && $end > $start && $start > 0) {
+            return $start + 1;
+        }
+
+        return $start;
+    }
+
     /** Concat destination must not alias an active catch variable slot (#17384). */
     private function concatResultSlotAliasesCatchVar(int $slot): bool
     {
@@ -12933,20 +12983,20 @@ protected function compileOp(Op $op, Block $block) {
                 $empty = new Operand\Literal('');
                 $empty->type = Type::string();
                 $emptySlot = $this->compileOperand($empty, $block, true);
-                $block->addOpCode(new OpCode(
+                $this->addConcatListOpCode($block, new OpCode(
                     OpCode::TYPE_ASSIGN,
                     $return,
                     $return,
                     $emptySlot
-                ));
+                ), $op);
             } elseif (1 === $total) {
                 // Zend string context for a lone encapsed variable (#4785) — not a plain assign.
                 $part = $this->compileConcatListPart($op->list[0], $block);
-                $block->addOpCode(new OpCode(
+                $this->addConcatListOpCode($block, new OpCode(
                     OpCode::TYPE_CAST_STRING,
                     $return,
                     $part
-                ));
+                ), $op);
             } else {
                 // Encapsed ConcatList used to emit in-place CONCAT($return, $return, $right).
                 // Reusing one dead-temp slot for every link intermittently heap-corrupts under
@@ -12959,12 +13009,12 @@ protected function compileOp(Op $op, Block $block) {
                     $dest = $isLast
                         ? $return
                         : $block->forceFreshVarSlot(new Temporary());
-                    $block->addOpCode(new OpCode(
+                    $this->addConcatListOpCode($block, new OpCode(
                         OpCode::TYPE_CONCAT,
                         $dest,
                         $acc,
                         $right
-                    ));
+                    ), $op);
                     $acc = $dest;
                 }
             }
diff --git a/lib/JIT.php b/lib/JIT.php
index 98cbc7c66be..090977c389e 100644
--- a/lib/JIT.php
+++ b/lib/JIT.php
@@ -8135,6 +8135,10 @@ private function compileBlockInternal(
 
         for ($i = $startIndex, $length = null !== $limit ? $limit : count($block->opCodes); $i < $length; ++$i) {
             $op = $block->opCodes[$i];
+            // Current opline for runtime warnings (encapsed CONCAT FETCH_R, #32034).
+            if (null !== $op->sourceLocation && $op->sourceLocation->startLine > 0) {
+                $this->context->callSiteLine = $op->sourceLocation->startLine;
+            }
             if (
                 null !== $block->func
                 && '{main}' === $block->func->name
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 0b5d52cdc0b..923c2c2ca90 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -280,6 +280,8 @@
             <file>./test/compliance/DynamicPropAssignWithGetNoSet31949JITTest.php</file>
             <file>./test/compliance/ListDestructUndefKeyLine31994VMTest.php</file>
             <file>./test/compliance/ListDestructUndefKeyLine31994JITTest.php</file>
+            <file>./test/compliance/EncapsedUndefVarWarningLine32034VMTest.php</file>
+            <file>./test/compliance/EncapsedUndefVarWarningLine32034JITTest.php</file>
             <file>./test/compliance/VarDumpUninitTypedProperty31147VMTest.php</file>
             <file>./test/compliance/VarDumpUninitTypedProperty31147JITTest.php</file>
             <file>./test/compliance/InOperatorPhpSrcReject31158VMTest.php</file>
diff --git a/test/compliance/EncapsedUndefVarWarningLine32034JITTest.php b/test/compliance/EncapsedUndefVarWarningLine32034JITTest.php
new file mode 100644
index 00000000000..dfc797a19b0
--- /dev/null
+++ b/test/compliance/EncapsedUndefVarWarningLine32034JITTest.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler;
+
+require_once __DIR__.'/../BaseTest.php';
+
+/**
+ * JIT: encapsed/heredoc Undefined variable Warning cites user site (#32034).
+ *
+ * Dedicated provider — path-slash data-set names break --filter on full JITTest.
+ *
+ * @group llvm
+ */
+final class EncapsedUndefVarWarningLine32034JITTest extends BaseTest
+{
+    protected static string $DIR = __DIR__;
+
+    public static function providePHPTests(): \Generator
+    {
+        yield 'encapsed_undef_var_warning_line.phpt' => self::parsePHPT(
+            __DIR__.'/cases/language/encapsed_undef_var_warning_line.phpt',
+            'encapsed_undef_var_warning_line.phpt'
+        );
+    }
+
+    public function setUp(): void
+    {
+        $this->BIN = realpath(__DIR__.'/../../bin/jit.php');
+    }
+}
diff --git a/test/compliance/EncapsedUndefVarWarningLine32034VMTest.php b/test/compliance/EncapsedUndefVarWarningLine32034VMTest.php
new file mode 100644
index 00000000000..4a220f27fec
--- /dev/null
+++ b/test/compliance/EncapsedUndefVarWarningLine32034VMTest.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler;
+
+require_once __DIR__.'/../BaseTest.php';
+
+/**
+ * VM: encapsed/heredoc Undefined variable Warning cites user site (#32034).
+ *
+ * Dedicated provider — path-slash data-set names break --filter on full VMTest.
+ */
+final class EncapsedUndefVarWarningLine32034VMTest extends BaseTest
+{
+    protected static string $DIR = __DIR__;
+
+    public static function providePHPTests(): \Generator
+    {
+        yield 'encapsed_undef_var_warning_line.phpt' => self::parsePHPT(
+            __DIR__.'/cases/language/encapsed_undef_var_warning_line.phpt',
+            'encapsed_undef_var_warning_line.phpt'
+        );
+    }
+
+    public function setUp(): void
+    {
+        $this->BIN = realpath(__DIR__.'/../../bin/vm.php');
+    }
+}
diff --git a/test/compliance/cases/language/encapsed_undef_var_warning_line.phpt b/test/compliance/cases/language/encapsed_undef_var_warning_line.phpt
new file mode 100644
index 00000000000..59049653d9b
--- /dev/null
+++ b/test/compliance/cases/language/encapsed_undef_var_warning_line.phpt
@@ -0,0 +1,33 @@
+--TEST--
+Language: encapsed/heredoc Undefined variable Warning cites user site (#32034, Zend/zend_compile.c)
+--FILE--
+<?php
+function warn_line(int $errno, string $message, string $file, int $line): bool
+{
+    if (E_WARNING === $errno) {
+        echo 'W:', $message, '@', $line, "\n";
+    }
+
+    return true;
+}
+set_error_handler('warn_line');
+
+echo "x=$missing_dq\n";
+$s = "a$missing_asg b";
+$s = "a{$missing_brace} b";
+echo "${missing_dollar}\n";
+$h = <<<EOT
+a$missing_heredoc
+EOT;
+echo $missing_plain;
+echo "done\n";
+--EXPECT--
+W:Undefined variable $missing_dq@12
+x=
+W:Undefined variable $missing_asg@13
+W:Undefined variable $missing_brace@14
+W:Undefined variable $missing_dollar@15
+
+W:Undefined variable $missing_heredoc@17
+W:Undefined variable $missing_plain@19
+done
diff --git a/test/repro/maintainer_gap_undef_var_encapsed_line.php b/test/repro/maintainer_gap_undef_var_encapsed_line.php
new file mode 100644
index 00000000000..d6e04efe984
--- /dev/null
+++ b/test/repro/maintainer_gap_undef_var_encapsed_line.php
@@ -0,0 +1,6 @@
+<?php
+error_reporting(E_ALL);
+echo "x=$missing\n";
+$s = "a$missing b";
+$s = "a{$missing} b";
+echo "${missing}\n";
diff --git a/test/repro/maintainer_gap_undef_var_heredoc_line.php b/test/repro/maintainer_gap_undef_var_heredoc_line.php
new file mode 100644
index 00000000000..a050b273e97
--- /dev/null
+++ b/test/repro/maintainer_gap_undef_var_heredoc_line.php
@@ -0,0 +1,5 @@
+<?php
+error_reporting(E_ALL);
+$s = <<<EOT
+a$missing
+EOT;
diff --git a/test/repro/maintainer_gap_undef_var_line.php b/test/repro/maintainer_gap_undef_var_line.php
new file mode 100644
index 00000000000..a0496aae11f
--- /dev/null
+++ b/test/repro/maintainer_gap_undef_var_line.php
@@ -0,0 +1,3 @@
+<?php
+error_reporting(E_ALL);
+echo $missing;
diff --git a/test/unit/UndefinedVariableWarningLineTest.php b/test/unit/UndefinedVariableWarningLineTest.php
index 2fa527ba03c..62e71c7f932 100644
--- a/test/unit/UndefinedVariableWarningLineTest.php
+++ b/test/unit/UndefinedVariableWarningLineTest.php
@@ -55,6 +55,46 @@ public function testBinaryExprUndefinedVariableWarningIncludesLineSuffix(): void
         );
     }
 
+    public function testEncapsedUndefinedVariableWarningCitesExpressionLine(): void
+    {
+        $script = $this->repoRoot.'/test/repro/maintainer_gap_undef_var_encapsed_line.php';
+        [, $stderr] = $this->runVmScript($script, 0);
+        $this->assertMatchesRegularExpression(
+            '/Undefined variable \$missing in .+maintainer_gap_undef_var_encapsed_line\.php on line 3/m',
+            $stderr
+        );
+        $this->assertMatchesRegularExpression(
+            '/Undefined variable \$missing in .+maintainer_gap_undef_var_encapsed_line\.php on line 4/m',
+            $stderr
+        );
+        $this->assertMatchesRegularExpression(
+            '/Undefined variable \$missing in .+maintainer_gap_undef_var_encapsed_line\.php on line 5/m',
+            $stderr
+        );
+        $this->assertMatchesRegularExpression(
+            '/Undefined variable \$missing in .+maintainer_gap_undef_var_encapsed_line\.php on line 6/m',
+            $stderr
+        );
+        $this->assertDoesNotMatchRegularExpression(
+            '/Undefined variable \$missing in .+maintainer_gap_undef_var_encapsed_line\.php on line 2/m',
+            $stderr
+        );
+    }
+
+    public function testHeredocUndefinedVariableWarningCitesBodyLine(): void
+    {
+        $script = $this->repoRoot.'/test/repro/maintainer_gap_undef_var_heredoc_line.php';
+        [, $stderr] = $this->runVmScript($script, 0);
+        $this->assertMatchesRegularExpression(
+            '/Undefined variable \$missing in .+maintainer_gap_undef_var_heredoc_line\.php on line 4\s*$/m',
+            $stderr
+        );
+        $this->assertDoesNotMatchRegularExpression(
+            '/Undefined variable \$missing in .+maintainer_gap_undef_var_heredoc_line\.php on line 2/m',
+            $stderr
+        );
+    }
+
     /**
      * @return array{0: string, 1: string}
      */