diff --git a/build/tools/release.sh b/build/tools/release.sh
index 68dab59daa..967702c70b 100755
--- a/build/tools/release.sh
+++ b/build/tools/release.sh
@@ -37,7 +37,14 @@ trap cleanup INT TERM EXIT
 cleanup
 
 mkdir -p $destdir
-git archive --prefix=$prefix/ HEAD | (cd $destdir; tar x)
+
+# We use GNU tar -i option to allow successfully extracting files from several
+# tar archives concatenated together, without it we'd have to pipe output of
+# each git-archive separately.
+(git archive --prefix=$prefix/ HEAD;
+ git submodule foreach --quiet "cd $root/\$path && git archive --prefix=$prefix/\$path/ HEAD") |
+tar x -C $destdir -i
+
 cd $destdir
 # All setup0.h files are supposed to be renamed to just setup.h when checked
 # out and in the distribution.
diff --git a/docs/contributing/how-to-release.md b/docs/contributing/how-to-release.md
index a3a5a7aa6e..0285addaa9 100644
--- a/docs/contributing/how-to-release.md
+++ b/docs/contributing/how-to-release.md
@@ -2,7 +2,7 @@
 
 Creating a new release requires a few things before getting started:
 
-* Linux or OSX.
+* Linux (or another Unix but GNU tar is required).
 * Windows 7+ with HTML Help Workshop, and Inno Setup installed.
 * 7-Zip, Doxygen 1.8.8, and GraphViz installed on both machines.