diff --git a/arcup/arcup b/arcup/arcup
index 3590cd3..b6510ea 100755
--- a/arcup/arcup
+++ b/arcup/arcup
@@ -261,17 +261,24 @@ download_error() {
 version_gt() {
     [ "$1" = "$2" ] && return 1
 
-    # Remove 'v' prefix if present
-    local ver1="${1#v}"
-    local ver2="${2#v}"
-    ver1="${ver1%%-*}"
-    ver2="${ver2%%-*}"
-
+    # Remove 'v' prefix and strip build metadata (+...) up front. SemVer ignores
+    # build metadata for precedence, and stripping it first prevents a '-' inside
+    # build metadata (e.g. 1.0.0+build-1) from being misread as a prerelease.
+    local v1="${1#v}"; v1="${v1%%+*}"
+    local v2="${2#v}"; v2="${v2%%+*}"
+
+    # Split into core "major.minor.patch" and optional prerelease.
+    local core1="${v1%%-*}" pre1=""
+    [ "$v1" = "$core1" ] || pre1="${v1#*-}"
+    local core2="${v2%%-*}" pre2=""
+    [ "$v2" = "$core2" ] || pre2="${v2#*-}"
+
+    local major1 minor1 patch1 major2 minor2 patch2
     IFS=. read -r major1 minor1 patch1 <<EOF
-$ver1
+$core1
 EOF
     IFS=. read -r major2 minor2 patch2 <<EOF
-$ver2
+$core2
 EOF
 
     [ "$major1" -gt "$major2" ] && return 0
@@ -281,6 +288,38 @@ EOF
     [ "$patch1" -gt "$patch2" ] && return 0
     [ "$patch1" -lt "$patch2" ] && return 1
 
+    # Core versions are equal: apply SemVer prerelease precedence (semver.org section 11).
+    # A version WITHOUT a prerelease outranks the same version WITH one.
+    [ -z "$pre1" ] && [ -z "$pre2" ] && return 1
+    [ -z "$pre1" ] && return 0
+    [ -z "$pre2" ] && return 1
+
+    # Both have a prerelease: compare dot-separated identifiers left to right.
+    # `read -ra` splits on IFS without pathname (glob) expansion.
+    local LC_ALL=C
+    local -a a1 a2
+    IFS=. read -ra a1 <<< "$pre1"
+    IFS=. read -ra a2 <<< "$pre2"
+    local max=${#a1[@]}
+    [ "${#a2[@]}" -gt "$max" ] && max=${#a2[@]}
+    local i id1 id2
+    for ((i = 0; i < max; i++)); do
+        id1="${a1[i]-}"; id2="${a2[i]-}"
+        [ -z "$id1" ] && return 1   # fewer identifiers -> lower precedence
+        [ -z "$id2" ] && return 0   # more identifiers  -> higher precedence
+        [ "$id1" = "$id2" ] && continue
+        if [[ "$id1" =~ ^[0-9]+$ ]] && [[ "$id2" =~ ^[0-9]+$ ]]; then
+            [ "$id1" -gt "$id2" ] && return 0
+            [ "$id1" -lt "$id2" ] && return 1
+        elif [[ "$id1" =~ ^[0-9]+$ ]]; then
+            return 1   # numeric identifiers rank lower than alphanumeric
+        elif [[ "$id2" =~ ^[0-9]+$ ]]; then
+            return 0
+        else
+            [[ "$id1" > "$id2" ]] && return 0
+            [[ "$id1" < "$id2" ]] && return 1
+        fi
+    done
     return 1
 }
 
diff --git a/arcup/version_gt_test.sh b/arcup/version_gt_test.sh
new file mode 100644
index 0000000..4318e7d
--- /dev/null
+++ b/arcup/version_gt_test.sh
@@ -0,0 +1,82 @@
+#!/usr/bin/env bash
+#
+# Tests for version_gt() in ./arcup (SemVer precedence, semver.org section 11).
+#
+# Usage:
+#   bash arcup/version_gt_test.sh
+#
+# It sources ./arcup with ARCUP_SKIP_MAIN=1 so only the function definitions load
+# (the installer's main flow is skipped) and then exercises version_gt().
+
+HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+export ARCUP_SKIP_MAIN=1
+# shellcheck source=./arcup disable=SC1091
+source "$HERE/arcup"
+# arcup runs under `set -euo pipefail`; relax it so the harness controls flow.
+set +eu +o pipefail 2>/dev/null || true
+
+pass=0
+fail=0
+
+# assert_gt A B  -> expect version_gt to report A > B (exit 0)
+assert_gt() {
+    if version_gt "$1" "$2"; then
+        pass=$((pass + 1))
+    else
+        echo "FAIL: expected '$1' > '$2'"
+        fail=$((fail + 1))
+    fi
+}
+
+# assert_le A B  -> expect version_gt to report NOT A > B (exit non-zero)
+assert_le() {
+    if version_gt "$1" "$2"; then
+        echo "FAIL: expected NOT '$1' > '$2'"
+        fail=$((fail + 1))
+    else
+        pass=$((pass + 1))
+    fi
+}
+
+# Reported bug (#205): prerelease vs stable and prerelease vs prerelease
+assert_gt "0.3.0" "0.3.0-rc.1"
+assert_le "0.3.0-rc.1" "0.3.0"
+assert_gt "0.3.0-rc.2" "0.3.0-rc.1"
+assert_le "0.3.0-rc.1" "0.3.0-rc.2"
+
+# Core major.minor.patch comparisons (with and without 'v' prefix)
+assert_gt "1.0.0" "0.9.9"
+assert_le "0.9.9" "1.0.0"
+assert_gt "v1.2.4" "v1.2.3"
+assert_le "1.2.3" "1.2.3"
+assert_gt "1.3.0" "1.2.9"
+assert_gt "2.0.0-rc.1" "1.9.9"
+
+# Full SemVer 11.4 precedence chain:
+# 1.0.0-alpha < 1.0.0-alpha.1 < 1.0.0-alpha.beta < 1.0.0-beta
+#            < 1.0.0-beta.2 < 1.0.0-beta.11 < 1.0.0-rc.1 < 1.0.0
+assert_gt "1.0.0-alpha.1" "1.0.0-alpha"
+assert_gt "1.0.0-alpha.beta" "1.0.0-alpha.1"
+assert_gt "1.0.0-beta" "1.0.0-alpha.beta"
+assert_gt "1.0.0-beta.2" "1.0.0-beta"
+assert_gt "1.0.0-beta.11" "1.0.0-beta.2"
+assert_gt "1.0.0-rc.1" "1.0.0-beta.11"
+assert_gt "1.0.0" "1.0.0-rc.1"
+
+# Build metadata is ignored for precedence
+assert_le "1.0.0+build.9" "1.0.0+build.1"
+assert_le "1.0.0" "1.0.0+build.1"
+
+# Build metadata containing a hyphen must NOT be treated as a prerelease
+assert_le "1.0.0+build-123" "1.0.0"
+assert_le "1.0.0" "1.0.0+build-123"
+assert_gt "1.0.1+build-1" "1.0.0"
+
+# Prerelease combined with build metadata: build metadata is ignored, so
+# precedence is decided purely by the prerelease identifiers.
+assert_le "1.0.0-rc.1+build-123" "1.0.0-rc.1"
+assert_le "1.0.0-rc.1" "1.0.0-rc.1+build-123"
+assert_gt "1.0.0-rc.2+build-1" "1.0.0-rc.1+build-99"
+
+echo "version_gt: ${pass} passed, ${fail} failed"
+[ "${fail}" -eq 0 ]