diff --git a/build.sh b/build.sh
index 9c24d4db5..d780a641b 100755
--- a/build.sh
+++ b/build.sh
@@ -6,10 +6,34 @@
 
 set -eu -o pipefail
 
-VERSION="1.0.3"
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 RELEASE_DIR="$SCRIPT_DIR/release"
 
+# Derive the release version from configure.ac instead of hardcoding it here.
+# A stale literal names the release directories after the wrong version while the
+# binaries inside report the real one: this said 1.0.3 while the tree was already
+# 1.1.0, so `./build.sh --all-release` would have produced
+# release/dragonx-1.0.3-<platform>/ full of binaries announcing 1.1.0.
+# Mirrors configure.ac's _CLIENT_VERSION_SUFFIX m4 exactly:
+#   build < 25 -> beta(build+1)   build < 50 -> rc(build-24)
+#   build == 50 -> plain release  build > 50 -> point release (build-50)
+_acdef() { sed -n "s/^define(_CLIENT_VERSION_$1, *\([0-9]\{1,\}\))/\1/p" "$SCRIPT_DIR/configure.ac"; }
+_V_MAJOR="$(_acdef MAJOR)"
+_V_MINOR="$(_acdef MINOR)"
+_V_REVISION="$(_acdef REVISION)"
+_V_BUILD="$(_acdef BUILD)"
+if [ -z "$_V_MAJOR" ] || [ -z "$_V_MINOR" ] || [ -z "$_V_REVISION" ] || [ -z "$_V_BUILD" ]; then
+    echo "ERROR: could not read the version from $SCRIPT_DIR/configure.ac" >&2
+    echo "       refusing to build a release whose directory name would be wrong." >&2
+    exit 1
+fi
+if   [ "$_V_BUILD" -lt 25 ]; then _V_SUFFIX="$_V_REVISION-beta$((_V_BUILD + 1))"
+elif [ "$_V_BUILD" -lt 50 ]; then _V_SUFFIX="$_V_REVISION-rc$((_V_BUILD - 24))"
+elif [ "$_V_BUILD" -eq 50 ]; then _V_SUFFIX="$_V_REVISION"
+else                              _V_SUFFIX="$_V_REVISION-$((_V_BUILD - 50))"
+fi
+VERSION="$_V_MAJOR.$_V_MINOR.$_V_SUFFIX"
+
 # Parse release flags
 BUILD_LINUX_RELEASE=0
 BUILD_WIN_RELEASE=0