diff --git a/hll/build.gradle.kts b/hll/build.gradle.kts
index ddd1bdcee90..0efc2348f62 100644
--- a/hll/build.gradle.kts
+++ b/hll/build.gradle.kts
@@ -5,8 +5,6 @@
 
 import aws.sdk.kotlin.gradle.dsl.configurePublishing
 import aws.sdk.kotlin.gradle.kmp.*
-import aws.smithy.kotlin.runtime.InternalApi
-import aws.smithy.kotlin.runtime.text.ensureSuffix
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 
 description = "High-level libraries for the AWS SDK for Kotlin"
@@ -34,7 +32,8 @@ val optinAnnotations = listOf(
     "kotlin.RequiresOptIn",
 )
 
-@OptIn(InternalApi::class)
+private fun String.ensureSuffix(suffix: String): String = if (endsWith(suffix)) this else plus(suffix)
+
 val hllPreviewVersion = if (sdkVersion.contains("-SNAPSHOT")) { // e.g. 1.3.29-beta-SNAPSHOT
     sdkVersion
         .removeSuffix("-SNAPSHOT")
diff --git a/hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/build.gradle.kts b/hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/build.gradle.kts
index e8ea582c245..74d16d4f439 100644
--- a/hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/build.gradle.kts
+++ b/hll/dynamodb-mapper/dynamodb-mapper-schema-generator-plugin/build.gradle.kts
@@ -1,5 +1,3 @@
-import aws.smithy.kotlin.runtime.InternalApi
-import aws.smithy.kotlin.runtime.text.ensureSuffix
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 /*
@@ -90,7 +88,8 @@ tasks.test {
 // FIXME Commonize the following functions into the aws-kotlin-repo-tools build-support
 val sdkVersion: String by project
 
-@OptIn(InternalApi::class)
+private fun String.ensureSuffix(suffix: String): String = if (endsWith(suffix)) this else plus(suffix)
+
 val hllPreviewVersion = if (sdkVersion.contains("-SNAPSHOT")) { // e.g. 1.3.29-beta-SNAPSHOT
     sdkVersion
         .removeSuffix("-SNAPSHOT")