diff --git a/src/Standards/PEAR/Sniffs/Functions/FunctionCallSignatureSniff.php b/src/Standards/PEAR/Sniffs/Functions/FunctionCallSignatureSniff.php
index 782a733aa5..0ad6cf4fc4 100644
--- a/src/Standards/PEAR/Sniffs/Functions/FunctionCallSignatureSniff.php
+++ b/src/Standards/PEAR/Sniffs/Functions/FunctionCallSignatureSniff.php
@@ -511,6 +511,12 @@ public function processMultiLineCall(File $phpcsFile, int $stackPtr, int $openBr
                         $expectedIndent = ($foundFunctionIndent + $this->indent + $adjustment);
                     }
 
+                    if ($tokens[$i]['code'] === T_END_HEREDOC
+                        || $tokens[$i]['code'] === T_END_NOWDOC
+                    ) {
+                        continue;
+                    }
+
                     if ($tokens[$i]['code'] !== T_WHITESPACE
                         && $tokens[$i]['code'] !== T_DOC_COMMENT_WHITESPACE
                     ) {
@@ -551,7 +557,10 @@ public function processMultiLineCall(File $phpcsFile, int $stackPtr, int $openBr
                             $padding = str_repeat(' ', $expectedIndent);
                             if ($foundIndent === 0) {
                                 $phpcsFile->fixer->addContentBefore($i, $padding);
-                                if (isset($tokens[$i]['scope_opener']) === true) {
+                                if (isset($tokens[$i]['scope_opener']) === true
+                                    && $tokens[$i]['code'] !== T_START_HEREDOC
+                                    && $tokens[$i]['code'] !== T_START_NOWDOC
+                                ) {
                                     $phpcsFile->fixer->changeCodeBlockIndent($i, $tokens[$i]['scope_closer'], $expectedIndent);
                                 }
                             } else {
@@ -562,7 +571,10 @@ public function processMultiLineCall(File $phpcsFile, int $stackPtr, int $openBr
                                     $phpcsFile->fixer->replaceToken($i, $padding);
                                 }
 
-                                if (isset($tokens[($i + 1)]['scope_opener']) === true) {
+                                if (isset($tokens[($i + 1)]['scope_opener']) === true
+                                    && $tokens[($i + 1)]['code'] !== T_START_HEREDOC
+                                    && $tokens[($i + 1)]['code'] !== T_START_NOWDOC
+                                ) {
                                     $phpcsFile->fixer->changeCodeBlockIndent(($i + 1), $tokens[($i + 1)]['scope_closer'], ($expectedIndent - $foundIndent));
                                 }
                             }
diff --git a/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.inc b/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.inc
index 3006081105..7ccfe2b11b 100644
--- a/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.inc
+++ b/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.inc
@@ -609,3 +609,10 @@ $anon = new class () {};
 
 // And anonymous object instantiations without parentheses are ignored.
 $anon = new class {};
+
+// Flexible heredoc in multiline function call.
+<?php if (1) f(
+  <<<E
+	x
+E
+);
diff --git a/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.inc.fixed b/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.inc.fixed
index ca29fc1a65..f9ad902b7d 100644
--- a/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.inc.fixed
+++ b/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.inc.fixed
@@ -628,3 +628,10 @@ $anon = new class () {};
 
 // And anonymous object instantiations without parentheses are ignored.
 $anon = new class {};
+
+// Flexible heredoc in multiline function call.
+<?php if (1) f(
+    <<<E
+	x
+E
+);
diff --git a/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.php b/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.php
index 023add9b6e..b8cb30b3cf 100644
--- a/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.php
+++ b/src/Standards/PEAR/Tests/Functions/FunctionCallSignatureUnitTest.php
@@ -129,6 +129,7 @@ public function getErrorList()
             603 => 1,
             604 => 1,
             605 => 2,
+            615 => 1,
         ];
     }