diff --git a/test/cpp/interop/client_helper.cc b/test/cpp/interop/client_helper.cc
index b8a222c54a0e6c48fbd453ce72e0269a58c8ccef..da5627de95db95501fac753d3cd2627d7fc09c16 100644
--- a/test/cpp/interop/client_helper.cc
+++ b/test/cpp/interop/client_helper.cc
@@ -52,7 +52,6 @@
 #include "test/core/security/oauth2_utils.h"
 #include "test/cpp/util/create_test_channel.h"
 
-#include "src/core/surface/call.h"
 #include "src/cpp/client/secure_credentials.h"
 
 DECLARE_bool(enable_ssl);
@@ -141,18 +140,5 @@ std::shared_ptr<ChannelInterface> CreateChannelForTestCase(
   }
 }
 
-InteropClientContextInspector::InteropClientContextInspector(
-    const ::grpc::ClientContext& context)
-    : context_(context) {}
-
-grpc_compression_algorithm
-InteropClientContextInspector::GetCallCompressionAlgorithm() const {
-  return grpc_call_get_compression_algorithm(context_.call_);
-}
-
-gpr_uint32 InteropClientContextInspector::GetMessageFlags() const {
-  return grpc_call_get_message_flags(context_.call_);
-}
-
 }  // namespace testing
 }  // namespace grpc
diff --git a/test/cpp/interop/client_helper.h b/test/cpp/interop/client_helper.h
index 000374ae8e375bb3518db2ec51a9ad879d33749e..edc69e90ace8f08bcca6d8c6e22b50b4657d2d8c 100644
--- a/test/cpp/interop/client_helper.h
+++ b/test/cpp/interop/client_helper.h
@@ -39,6 +39,8 @@
 #include <grpc++/config.h>
 #include <grpc++/channel_interface.h>
 
+#include "src/core/surface/call.h"
+
 namespace grpc {
 namespace testing {
 
@@ -51,11 +53,17 @@ std::shared_ptr<ChannelInterface> CreateChannelForTestCase(
 
 class InteropClientContextInspector {
  public:
-  InteropClientContextInspector(const ::grpc::ClientContext& context);
+  InteropClientContextInspector(const ::grpc::ClientContext& context)
+    : context_(context) {}
 
   // Inspector methods, able to peek inside ClientContext, follow.
-  grpc_compression_algorithm GetCallCompressionAlgorithm() const;
-  gpr_uint32 GetMessageFlags() const;
+  grpc_compression_algorithm GetCallCompressionAlgorithm() const {
+    return grpc_call_get_compression_algorithm(context_.call_);
+  }
+
+  gpr_uint32 GetMessageFlags() const {
+    return grpc_call_get_message_flags(context_.call_);
+  }
 
  private:
   const ::grpc::ClientContext& context_;