diff --git a/wasm-port/docs/compatibility-validation.md b/wasm-port/docs/compatibility-validation.md
index 056ce41..73deca8 100644
--- a/wasm-port/docs/compatibility-validation.md
+++ b/wasm-port/docs/compatibility-validation.md
@@ -110,6 +110,7 @@ parameter semantics, and that INI-derived machine file names are still
 rejected by the OPFS path model when they contain traversal or nested path
 segments. The same Node smoke also validates that explicit session file-name
 options take precedence over INI-derived parameter and tool-table file names,
+and that missing INI file-name values fall back to the host path model defaults,
 keeping host override policy outside CNC semantics.
 
 The browser INI/OPFS smoke script serves `wasm-port/` over localhost and runs
@@ -273,7 +274,8 @@ derived from vendored LinuxCNC INI boolean parsing, INI-derived
 `[RS274NGC]PARAMETER_FILE` and `[EMCIO]TOOL_TABLE` file names mapped to OPFS
 machine files, OPFS path-model rejection of invalid INI-derived file names,
 explicit host session file-name overrides taking precedence over INI-derived
-names, session snapshot custom filename handling plus envelope/path rejection
+names, default host path fallback when INI file-name values are absent,
+session snapshot custom filename handling plus envelope/path rejection
 for unsupported format/version, wrong session id, and invalid snapshot
 filenames, and a browser interpreter smoke that uses the same session bridge
 with real LinuxCNC INI WASM parsing before saving OPFS-backed parameter and
diff --git a/wasm-port/tests/opfs/node/verify_file_service.mjs b/wasm-port/tests/opfs/node/verify_file_service.mjs
index 9fec4ea..a8fd49a 100644
--- a/wasm-port/tests/opfs/node/verify_file_service.mjs
+++ b/wasm-port/tests/opfs/node/verify_file_service.mjs
@@ -441,6 +441,14 @@ assert.equal(
   loadedIniDerivedRandomSession.toolTable.result,
   "tooldata_load=0\nload_tool_path=/work/ini-derived-session-tool.tbl\nrandom_toolchanger=1\n",
 );
+assert.equal(
+  loadedIniDerivedRandomSession.parameters.opfsPath,
+  "linuxcnc/machines/xyzab-tdr/linuxcnc.var",
+);
+assert.equal(
+  loadedIniDerivedRandomSession.toolTable.opfsPath,
+  "linuxcnc/machines/xyzab-tdr/tool.tbl",
+);
 
 await saveMachineTextFiles("ini-file-session", {
   ini: [