diff --git a/codegen-serde/src/main/kotlin/software/amazon/smithy/rust/codegen/serde/SerializeImplGenerator.kt b/codegen-serde/src/main/kotlin/software/amazon/smithy/rust/codegen/serde/SerializeImplGenerator.kt
index 66b806cdbaed0999d20d24331dce0222639bc4f7..1ef9a3033ef93321828b8c6930779930615d87a1 100644
--- a/codegen-serde/src/main/kotlin/software/amazon/smithy/rust/codegen/serde/SerializeImplGenerator.kt
+++ b/codegen-serde/src/main/kotlin/software/amazon/smithy/rust/codegen/serde/SerializeImplGenerator.kt
@@ -556,6 +556,7 @@ class SerializeImplGenerator(private val codegenContext: CodegenContext) {
             }
             """,
             "Shape" to shape, "body" to block, *SupportStructures.codegenScope,
+            *RuntimeType.preludeScope,
         )
     }
 
@@ -578,6 +579,7 @@ class SerializeImplGenerator(private val codegenContext: CodegenContext) {
                 }
                 """,
                 "Shape" to shape, "body" to block, *SupportStructures.codegenScope,
+                *RuntimeType.preludeScope,
             )
         }
     }
diff --git a/codegen-serde/src/main/kotlin/software/amazon/smithy/rust/codegen/serde/SupportStructures.kt b/codegen-serde/src/main/kotlin/software/amazon/smithy/rust/codegen/serde/SupportStructures.kt
index 724e7fd8fb2f43b69f266c535d9705c715425ac8..03c4a18fe74c5834b5352631c7c3375c2dc3bf7c 100644
--- a/codegen-serde/src/main/kotlin/software/amazon/smithy/rust/codegen/serde/SupportStructures.kt
+++ b/codegen-serde/src/main/kotlin/software/amazon/smithy/rust/codegen/serde/SupportStructures.kt
@@ -23,7 +23,6 @@ object SupportStructures {
 
     val codegenScope =
         arrayOf(
-            *RuntimeType.preludeScope,
             "ConfigurableSerde" to configurableSerde(),
             "SerializeConfigured" to serializeConfigured(),
             "ConfigurableSerdeRef" to configurableSerdeRef(),
@@ -54,7 +53,7 @@ object SupportStructures {
                 "serde" to serde,
                 "SerializeConfigured" to serializeConfigured(),
                 "SerializationSettings" to serializationSettings(),
-                *codegenScope,
+                *RuntimeType.preludeScope,
             )
         }
 
@@ -78,7 +77,7 @@ object SupportStructures {
                 "serde" to serde,
                 "SerializeConfigured" to serializeConfigured(),
                 "SerializationSettings" to serializationSettings(),
-                *codegenScope,
+                *RuntimeType.preludeScope,
             )
         }
 
@@ -150,7 +149,7 @@ object SupportStructures {
                 }
                 """,
                 "serde" to CargoDependency.Serde.toType(),
-                *codegenScope,
+                *RuntimeType.preludeScope,
             )
         }
 
@@ -196,7 +195,7 @@ object SupportStructures {
                 "ConfigurableSerdeRef" to configurableSerdeRef(),
                 "SerializeConfigured" to serializeConfigured(),
                 "serde" to CargoDependency.Serde.toType(),
-                *codegenScope,
+                *RuntimeType.preludeScope,
             )
         }