diff --git a/core/src/main/kotlin/org/evomaster/core/problem/rest/data/RestPath.kt b/core/src/main/kotlin/org/evomaster/core/problem/rest/data/RestPath.kt
index 8331f87ca2..4e1439b4e6 100644
--- a/core/src/main/kotlin/org/evomaster/core/problem/rest/data/RestPath.kt
+++ b/core/src/main/kotlin/org/evomaster/core/problem/rest/data/RestPath.kt
@@ -413,7 +413,7 @@ class RestPath(path: String) {
                             why not using URI also for Query part???
                             it seems unclear how to properly build it as a single string...
                          */
-                        val entry = URI(null, null, path.toString(), null, null).rawPath
+                        val entry = URI(null, null, path.toString(), null, null).toASCIIString()
                         data.add(Pair(entry, false))
                         path.setLength(0) // clear it
                         data.add(Pair(variable, true))
@@ -446,7 +446,7 @@ class RestPath(path: String) {
         }
 
         if(path.isNotEmpty()){
-            val entry = URI(null, null, path.toString(), null, null).rawPath
+            val entry = URI(null, null, path.toString(), null, null).toASCIIString()
             data.add(Pair(entry, false))
         }
 
diff --git a/core/src/test/kotlin/org/evomaster/core/output/TestCaseWriterTest.kt b/core/src/test/kotlin/org/evomaster/core/output/TestCaseWriterTest.kt
index d2454da456..86fb37fc90 100644
--- a/core/src/test/kotlin/org/evomaster/core/output/TestCaseWriterTest.kt
+++ b/core/src/test/kotlin/org/evomaster/core/output/TestCaseWriterTest.kt
@@ -16,6 +16,7 @@ import org.evomaster.core.output.service.RestTestCaseWriter
 import org.evomaster.core.problem.enterprise.SampleType
 import org.evomaster.core.problem.rest.data.*
 import org.evomaster.core.problem.rest.param.BodyParam
+import org.evomaster.core.problem.rest.param.PathParam
 import org.evomaster.core.search.EvaluatedIndividual
 import org.evomaster.core.search.FitnessValue
 import org.evomaster.core.search.gene.*
@@ -28,6 +29,7 @@ import org.evomaster.core.search.gene.collection.EnumGene
 import org.evomaster.core.search.gene.numeric.IntegerGene
 import org.evomaster.core.search.gene.string.StringGene
 import org.evomaster.core.search.gene.utils.GeneUtils
+import org.evomaster.core.search.gene.wrapper.CustomMutationRateGene
 import org.evomaster.core.search.gene.wrapper.OptionalGene
 import org.evomaster.core.sql.schema.TableId
 import org.junit.jupiter.api.Assertions.*
@@ -1679,4 +1681,30 @@ public void test() throws Exception {
         assertFalse(lines.toString().contains(".body()"))
 
     }
+
+    @Test
+    fun testNonAsciiInPathParamIsEncoded() {
+        // non-ASCII characters in path parameter values must be percent-encoded in generated test output.
+        val format = OutputFormat.KOTLIN_JUNIT_5
+
+        val pathParam = PathParam("key", CustomMutationRateGene("key", StringGene("key", "聚"), 1.0))
+        val action = RestCallAction("1", HttpVerb.GET, RestPath("/api/{key}"), mutableListOf(pathParam))
+        val individual = RestIndividual(mutableListOf(action), SampleType.RANDOM)
+        TestUtils.doInitializeIndividualForTesting(individual)
+
+        val result = RestCallResult(action.getLocalId())
+        result.setTimedout(false)
+        result.setStatusCode(200)
+        val ei = EvaluatedIndividual(FitnessValue(0.0), individual, listOf(result))
+
+        val writer = RestTestCaseWriter(getConfig(format), PartialOracles())
+        val lines = writer.convertToCompilableTestCode(TestCase(test = ei, name = "test"), "baseUrlOfSut")
+        val output = lines.toString()
+
+        assertFalse(output.contains("聚"),
+            "Non-ASCII character must not appear raw in generated test output, got:\n$output")
+
+        assertTrue(output.contains("%E8%81%9A"),
+            "Non-ASCII character must be percent-encoded as %E8%81%9A in generated test output, got:\n$output")
+    }
 }
diff --git a/core/src/test/kotlin/org/evomaster/core/problem/rest/RestPathTest.kt b/core/src/test/kotlin/org/evomaster/core/problem/rest/RestPathTest.kt
index 7ddf3d809b..4ed357800f 100644
--- a/core/src/test/kotlin/org/evomaster/core/problem/rest/RestPathTest.kt
+++ b/core/src/test/kotlin/org/evomaster/core/problem/rest/RestPathTest.kt
@@ -605,4 +605,19 @@ internal class RestPathTest{
         assertEquals(y, resolvedY)
     }
 
+    @Test
+    fun testPathParamWithNonAscii() {
+        // Non-ASCII characters (e.g. from AnyCharacterRxGene sampling the full
+        // Unicode range) must also be percent-encoded in path parameters. These
+        // are not encoded by URI(null, null, s, null, null) in path parameters,
+        // causing them to appear raw in the generated URL.
+        val key = PathParam("key", CustomMutationRateGene("d_", StringGene("key", "key-聚"), 1.0))
+
+        val resolved = RestPath("/api/{key}").resolve(listOf(key))
+
+        assertFalse(resolved.contains("聚"),
+            "Resolved path must not contain a raw non-ASCII character, got: $resolved")
+        assertTrue(resolved.contains("%E8%81%9A"),
+            "Resolved path must percent-encode non-ASCII characters, got: $resolved")
+    }
 }
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