diff --git a/install.sh b/install.sh
index 6440bff0fc..1ea8afe479 100755
--- a/install.sh
+++ b/install.sh
@@ -792,24 +792,18 @@ find_rpm_asset() {
   _package="$3"
 
   case "$_package" in
-    openshell)
-      _dev_name="openshell-dev-${_arch}.rpm"
-      _fallback_re="^openshell-[0-9].*\\.${_arch}\\.rpm$"
-      ;;
-    openshell-gateway)
-      _dev_name="openshell-gateway-dev-${_arch}.rpm"
-      _fallback_re="^openshell-gateway-[0-9].*\\.${_arch}\\.rpm$"
-      ;;
-    openshell-prover)
-      _dev_name="openshell-prover-dev-${_arch}.rpm"
-      _fallback_re="^openshell-prover-[0-9].*\\.${_arch}\\.rpm$"
-      ;;
+    openshell|openshell-gateway|openshell-prover) ;;
     *)
       error "unknown RPM package selector: ${_package}"
       ;;
   esac
 
-  awk -v dev_name="$_dev_name" -v fallback_re="$_fallback_re" '
+  # Build the regex inside awk: -v values have their escapes processed.
+  awk -v package="$_package" -v arch="$_arch" '
+    BEGIN {
+      dev_name = package "-dev-" arch ".rpm"
+      fallback_re = "^" package "-[0-9].*\\." arch "\\.rpm$"
+    }
     {
       name = $2
       sub("^\\*", "", name)
diff --git a/tasks/scripts/test-install-sh.sh b/tasks/scripts/test-install-sh.sh
index 80ac03d2c6..fb5c382c8e 100755
--- a/tasks/scripts/test-install-sh.sh
+++ b/tasks/scripts/test-install-sh.sh
@@ -845,6 +845,32 @@ if [ "$(find_rpm_asset "${tmpdir}/checksums" x86_64 openshell-prover)" != "opens
   exit 1
 fi
 
+cat >"${tmpdir}/checksums" <<'EOF'
+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa  openshell-0.1.5-1xx86_64xrpm
+bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb  openshell-0.1.5-1.x86_64.rpm
+cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc  openshell-gateway-0.1.5-1.x86_64.rpm
+EOF
+
+# gawk warns on bad regex escapes; mawk does not. Prefer gawk when present.
+rpm_path="$PATH"
+if gawk_bin="$(command -v gawk)"; then
+  mkdir "${tmpdir}/gawk-bin"
+  ln -s "$gawk_bin" "${tmpdir}/gawk-bin/awk"
+  rpm_path="${tmpdir}/gawk-bin:${PATH}"
+fi
+
+rpm_err="${tmpdir}/rpm_err"
+if [ "$(PATH="$rpm_path" find_rpm_asset "${tmpdir}/checksums" x86_64 openshell 2>"$rpm_err")" != "openshell-0.1.5-1.x86_64.rpm" ] ||
+  [ "$(PATH="$rpm_path" find_rpm_asset "${tmpdir}/checksums" x86_64 openshell-gateway 2>>"$rpm_err")" != "openshell-gateway-0.1.5-1.x86_64.rpm" ]; then
+  echo "FAIL: RPM fallback must match a literal dot" >&2
+  exit 1
+fi
+if [ -s "$rpm_err" ]; then
+  echo "FAIL: RPM package selection must not print to stderr" >&2
+  cat "$rpm_err" >&2
+  exit 1
+fi
+
 mock_gh_log="${tmpdir}/gh.log"
 PLATFORM=linux
 linux_package_method() {