diff --git a/required/tools/array.dtx b/required/tools/array.dtx
index e77ef0a3b..b1dd33622 100644
--- a/required/tools/array.dtx
+++ b/required/tools/array.dtx
@@ -39,7 +39,7 @@
 %    \begin{macrocode}
 %<+package>\NeedsTeXFormat{LaTeX2e}[2024/06/01]
 %<+package>\ProvidesPackage{array}
-%<+package>         [2024/05/23 v2.6c Tabular extension package (FMi)]
+%<+package>         [2024/06/14 v2.6d Tabular extension package (FMi)]
 %
 % \fi
 %
@@ -2852,11 +2852,13 @@ Bug reports can be opened (category \texttt{#1}) at\\%
 %    \end{macrocode}
 %
 % \begin{macro}{\@preamerr}
+%   \changes{v2.6d}{2024/06/14}{Keep message sources out of L3 code (gh/1378)}
 %    We also have to redefine the error routine =\@preamerr= since
 %    new kind of errors are possible.
 %    The code for this macro is not perfect yet;
 %    it still needs too much memory.
 %    \begin{macrocode}
+\ExplSyntaxOff
 \def\@preamerr#1{\def\@tempd{{..} at wrong position: }%
    \PackageError{array}{%
    \ifcase #1 Illegal pream-token (\@nextchar): `c' used\or %0
@@ -2905,7 +2907,6 @@ Bug reports can be opened (category \texttt{#1}) at\\%
 % to define letters, to be used in the same way as the primitive
 % column specifiers, `c' `p' etc.
 %    \begin{macrocode}
-\ExplSyntaxOff  % this is really oldstyle using \@tfor :=
 \def\newcolumntype#1{%
 %    \end{macrocode}
 % "\NC@char" was added in V2.01 so that active characters, like "@" in
diff --git a/required/tools/changes.txt b/required/tools/changes.txt
index 82da1a47d..b61f93944 100644
--- a/required/tools/changes.txt
+++ b/required/tools/changes.txt
@@ -9,6 +9,11 @@ are not part of the distribution.
 All changes above are only part of the development branch for the next release.
 ================================================================================
 
+2024-06-14  David Carlisle  <David.Carlisle@latex-project.org>
+
+	* array.dtx move \ExplSyntaxOff earlier so error message spaces preserved gh/1378
+
+
 #########################
 # 2024-06-01 Release
 #########################
diff --git a/required/tools/testfiles/github-1378.lvt b/required/tools/testfiles/github-1378.lvt
new file mode 100644
index 000000000..7eacf7497
--- /dev/null
+++ b/required/tools/testfiles/github-1378.lvt
@@ -0,0 +1,14 @@
+\documentclass{article}
+\usepackage{array}
+\input{test2e}
+\begin{document}
+
+x $x$
+
+\START
+% The error message should show spaces
+\begin{tabular}{X}
+  1.23 \\
+\end{tabular}
+
+\END
\ No newline at end of file
diff --git a/required/tools/testfiles/github-1378.tlg b/required/tools/testfiles/github-1378.tlg
new file mode 100644
index 000000000..ba8dcc6e3
--- /dev/null
+++ b/required/tools/testfiles/github-1378.tlg
@@ -0,0 +1,9 @@
+This is a generated file for the LaTeX2e validation system.
+Don't change this file in any respect.
+! Package array Error:  Illegal pream-token (X): `c' used.
+See the array package documentation for explanation.
+Type  H <return>  for immediate help.
+ ...                                              
+l. ...\begin{tabular}{X}
+Try typing  <return>  to proceed.
+If that doesn't work, type  X <return>  to quit.