diff --git a/src/application/environment/environmentReplay.ts b/src/application/environment/environmentReplay.ts
index db83a8e524..730202da55 100644
--- a/src/application/environment/environmentReplay.ts
+++ b/src/application/environment/environmentReplay.ts
@@ -1,3 +1,4 @@
+import { decodedSegment } from "../../domain/analysisView/environmentStateRules.js";
 import type { AnalysisError } from "../../domain/analysisErrorBase.js";
 import { AnalysisInputError } from "../../domain/analysisErrorCore.js";
 import type { JsonValue } from "../../domain/jsonValue.js";
@@ -47,18 +48,9 @@ interface MatchScore {
   readonly exact: boolean;
 }
 
-/** A path segment percent-decoded, or as written when it is not valid percent-encoding. */
-export const decodedPathSegment = (segment: string): string => {
-  try {
-    return decodeURIComponent(segment);
-  } catch {
-    return segment;
-  }
-};
-
 /** Replay's path rule: a supplied value matches a recorded segment equal to it verbatim or after percent-decoding. */
 export const pathValueMatches = (segment: string, value: string): boolean =>
-  segment === value || decodedPathSegment(segment) === value;
+  segment === value || decodedSegment(segment) === value;
 
 /** Count how many supplied path and query values the recorded request line satisfies. */
 const scoreExchange = (
diff --git a/src/application/environment/environmentStateAnswer.ts b/src/application/environment/environmentStateAnswer.ts
index 184e50fc15..cfd6739661 100644
--- a/src/application/environment/environmentStateAnswer.ts
+++ b/src/application/environment/environmentStateAnswer.ts
@@ -1,6 +1,7 @@
 import { stateBodyJson } from "../../domain/analysisView/EnvironmentStateAccumulator.js";
 import {
   collectionPathOf,
+  decodedSegment,
   listItems,
   missingRequiredFields,
   renderStateEntity,
@@ -28,7 +29,6 @@ import {
 import type { JsonValue } from "../../domain/jsonValue.js";
 import { err, ok, type Result } from "../../domain/result.js";
 import {
-  decodedPathSegment,
   pathValueMatches,
   replayAnswer,
   replayEnvironmentTool,
@@ -243,7 +243,7 @@ export const namedEntity = (
   type: string,
   call: ItemCall,
 ): StateEntity | undefined => {
-  const ids = [...new Set([decodedPathSegment(call.id), call.id])];
+  const ids = [...new Set([decodedSegment(call.id), call.id])];
   const candidates = store
     .collectionsOf(type)
     .flatMap((collection) => {
diff --git a/src/domain/analysisView/environmentStateWriteRules.ts b/src/domain/analysisView/environmentStateWriteRules.ts
index bf315fee74..58a598a669 100644
--- a/src/domain/analysisView/environmentStateWriteRules.ts
+++ b/src/domain/analysisView/environmentStateWriteRules.ts
@@ -1,5 +1,6 @@
 import type { JsonValue } from "../jsonValue.js";
 import {
+  decodedSegment,
   isParam,
   normalizedPath,
   segmentsOf,
@@ -187,13 +188,7 @@ export const pathValuesOf = (
       if (segment !== value) return undefined;
       continue;
     }
-    let decoded = value;
-    try {
-      decoded = decodeURIComponent(value);
-    } catch {
-      decoded = value;
-    }
-    values.set(segment.slice(1, -1), decoded);
+    values.set(segment.slice(1, -1), decodedSegment(value));
   }
   return values;
 };