diff --git a/cmake_config.h.in b/cmake_config.h.in
index 64db4ade9e..fdf9aa4e34 100644
--- a/cmake_config.h.in
+++ b/cmake_config.h.in
@@ -98,12 +98,14 @@
   #define INCLUDE_FMT_RANGES <fmt/ranges.h>
   #define INCLUDE_FMT_OSTREAM <fmt/ostream.h>
 
-  #define VT_FMT_NAMESPACE namespace fmt
+  #define VT_FMT_NAMESPACE_BEGIN namespace fmt {
+  #define VT_FMT_NAMESPACE_END }
 #else
   #define INCLUDE_FMT_CORE <fmt-vt/core.h>
   #define INCLUDE_FMT_FORMAT <fmt-vt/format.h>
   #define INCLUDE_FMT_RANGES <fmt-vt/ranges.h>
   #define INCLUDE_FMT_OSTREAM <fmt-vt/ostream.h>
 
-  #define VT_FMT_NAMESPACE namespace fmt::vt
+  #define VT_FMT_NAMESPACE_BEGIN namespace fmt { inline namespace vt {
+  #define VT_FMT_NAMESPACE_END } }
 #endif
diff --git a/src/vt/rdma/rdma_common.h b/src/vt/rdma/rdma_common.h
index 47cacb70cb..3660aa7d7f 100644
--- a/src/vt/rdma/rdma_common.h
+++ b/src/vt/rdma/rdma_common.h
@@ -117,7 +117,7 @@ static constexpr ByteType rdma_default_byte_size = sizeof(char);
 
 }} //end namespace vt::rdma
 
-VT_FMT_NAMESPACE {
+VT_FMT_NAMESPACE_BEGIN
   template <>
   struct formatter<::vt::rdma::Type> : formatter<std::string_view> {
     template <typename FormatContext>
@@ -136,11 +136,13 @@ VT_FMT_NAMESPACE {
       case ::vt::rdma::Type::Uninitialized:
         name = "Uninitialized";
         break;
+      default:
+        name = fmt::format("{}", static_cast<std::underlying_type_t<::vt::rdma::Type>>(t));
       }
       return formatter<std::string_view>::format(name, ctx);
     }
   };
-} // VT_FMT_NAMESPACE
+VT_FMT_NAMESPACE_END
 
 #define PRINT_CHANNEL_TYPE(rdma_op_type) (                              \
   rdma_op_type == vt::rdma::Type::Get ? "rdma::Get" : (            \
diff --git a/src/vt/termination/interval/interval.h b/src/vt/termination/interval/interval.h
index 99da07d776..7d9a81c5e8 100644
--- a/src/vt/termination/interval/interval.h
+++ b/src/vt/termination/interval/interval.h
@@ -237,7 +237,7 @@ struct Interval;
 
 }}}
 
-VT_FMT_NAMESPACE {
+VT_FMT_NAMESPACE_BEGIN
   template <typename DomainT, DomainT sentinel>
   struct formatter<::vt::term::interval::Interval<DomainT, sentinel>>
     : formatter<std::string> {
@@ -249,6 +249,6 @@ VT_FMT_NAMESPACE {
         ctx.out(), "Interval[{}, {}]", interval.lower(), interval.upper());
     }
   };
-} // VT_FMT_NAMESPACE
+VT_FMT_NAMESPACE_END
 
 #endif /*INCLUDED_VT_TERMINATION_INTERVAL_INTERVAL_H*/
diff --git a/src/vt/timing/timing.h b/src/vt/timing/timing.h
index 7e7cc02a83..560efbd0b1 100644
--- a/src/vt/timing/timing.h
+++ b/src/vt/timing/timing.h
@@ -63,7 +63,7 @@ TimeType getCurrentTime();
 
 }} /* end namespace vt::timing */
 
-VT_FMT_NAMESPACE {
+VT_FMT_NAMESPACE_BEGIN
   template <>
   struct formatter<::vt::TimeTypeWrapper> {
     template <typename ParseContext>
@@ -79,6 +79,6 @@ VT_FMT_NAMESPACE {
     }
   };
 
-} // VT_FMT_NAMESPACE
+VT_FMT_NAMESPACE_END
 
 #endif /*INCLUDED_VT_TIMING_TIMING_H*/
diff --git a/src/vt/topos/index/dense/dense_array.h b/src/vt/topos/index/dense/dense_array.h
index 9a57c856e0..61e3b7fddf 100644
--- a/src/vt/topos/index/dense/dense_array.h
+++ b/src/vt/topos/index/dense/dense_array.h
@@ -159,7 +159,7 @@ static_assert(
 
 }}  // end namespace vt::index
 
-VT_FMT_NAMESPACE {
+VT_FMT_NAMESPACE_BEGIN
   template <typename IndexType, ::vt::index::NumDimensionsType ndim>
   struct formatter<::vt::index::DenseIndexArray<IndexType, ndim>>
     : formatter<std::array<IndexType, ndim>> {
@@ -170,7 +170,7 @@ VT_FMT_NAMESPACE {
       return formatter<std::array<IndexType, ndim>>::format(wrapper.dims, ctx);
     }
   };
-} // VT_FMT_NAMESPACE
+VT_FMT_NAMESPACE_END
 
 #include "vt/topos/index/dense/dense_array.impl.h"
 
diff --git a/src/vt/vrt/collection/balance/greedylb/greedylb.h b/src/vt/vrt/collection/balance/greedylb/greedylb.h
index 27177a6558..0ead714ee0 100644
--- a/src/vt/vrt/collection/balance/greedylb/greedylb.h
+++ b/src/vt/vrt/collection/balance/greedylb/greedylb.h
@@ -126,7 +126,7 @@ struct GreedyLB : LoadSamplerBaseLB {
 
 }}}} /* end namespace vt::vrt::collection::lb */
 
-VT_FMT_NAMESPACE {
+VT_FMT_NAMESPACE_BEGIN
   template <>
   struct formatter<::vt::vrt::collection::lb::DataDistStrategy>
     : formatter<std::string_view> {
@@ -149,6 +149,6 @@ VT_FMT_NAMESPACE {
     }
   };
 
-} // VT_FMT_NAMESPACE
+VT_FMT_NAMESPACE_END
 
 #endif /*INCLUDED_VT_VRT_COLLECTION_BALANCE_GREEDYLB_GREEDYLB_H*/
diff --git a/src/vt/vrt/collection/balance/lb_args_enum_converter.h b/src/vt/vrt/collection/balance/lb_args_enum_converter.h
index 050adfeb86..fa2dce3ccb 100644
--- a/src/vt/vrt/collection/balance/lb_args_enum_converter.h
+++ b/src/vt/vrt/collection/balance/lb_args_enum_converter.h
@@ -100,7 +100,7 @@ struct LBArgsEnumConverter {
       auto err = fmt::format(
         "LBArgsEnumConverter: enum '{}' value '{}' corresponding to LB "
         "argument '{}' does not have a string associated with it",
-        enum_type_, e, par_name_
+        enum_type_, static_cast<std::underlying_type_t<T>>(e), par_name_
       );
       vtAbort(err);
     }
diff --git a/src/vt/vrt/collection/balance/temperedlb/criterion.h b/src/vt/vrt/collection/balance/temperedlb/criterion.h
index 5f1e278771..1f7d7784b4 100644
--- a/src/vt/vrt/collection/balance/temperedlb/criterion.h
+++ b/src/vt/vrt/collection/balance/temperedlb/criterion.h
@@ -93,7 +93,7 @@ struct Criterion {
 
 }}}} /* end namespace vt::vrt::collection::lb */
 
-VT_FMT_NAMESPACE {
+VT_FMT_NAMESPACE_BEGIN
   template <>
   struct formatter<::vt::vrt::collection::lb::CriterionEnum>
     : formatter<std::string_view> {
@@ -113,6 +113,6 @@ VT_FMT_NAMESPACE {
     }
   };
 
-} // VT_FMT_NAMESPACE
+VT_FMT_NAMESPACE_END
 
 #endif /*INCLUDED_VT_VRT_COLLECTION_BALANCE_TEMPEREDLB_CRITERION_H*/
diff --git a/src/vt/vrt/collection/balance/temperedlb/tempered_enums.h b/src/vt/vrt/collection/balance/temperedlb/tempered_enums.h
index 8c2ca050c7..b56414a333 100644
--- a/src/vt/vrt/collection/balance/temperedlb/tempered_enums.h
+++ b/src/vt/vrt/collection/balance/temperedlb/tempered_enums.h
@@ -167,103 +167,4 @@ enum struct KnowledgeEnum : uint8_t {
 
 }}}} /* end namespace vt::vrt::collection::lb */
 
-VT_FMT_NAMESPACE {
-  // Specialize fmt::formatter for ObjectOrderEnum
-  template <>
-  struct formatter<::vt::vrt::collection::lb::ObjectOrderEnum>
-    : formatter<std::string_view> {
-    template <typename FormatContext>
-    auto
-    format(::vt::vrt::collection::lb::ObjectOrderEnum c, FormatContext& ctx) {
-      std::string_view name = "Unknown";
-      switch (c) {
-      case ::vt::vrt::collection::lb::ObjectOrderEnum::Arbitrary:
-        name = "Arbitrary";
-        break;
-      case ::vt::vrt::collection::lb::ObjectOrderEnum::ElmID:
-        name = "ElmID";
-        break;
-      case ::vt::vrt::collection::lb::ObjectOrderEnum::FewestMigrations:
-        name = "FewestMigrations";
-        break;
-      case ::vt::vrt::collection::lb::ObjectOrderEnum::SmallObjects:
-        name = "SmallObjects";
-        break;
-      case ::vt::vrt::collection::lb::ObjectOrderEnum::LargestObjects:
-        name = "LargestObjects";
-        break;
-      }
-      return formatter<string_view>::format(name, ctx);
-    }
-  };
-
-  // Specialize fmt::formatter for CMFTypeEnum
-  template <>
-  struct formatter<::vt::vrt::collection::lb::CMFTypeEnum>
-    : formatter<std::string_view> {
-    template <typename FormatContext>
-    auto format(::vt::vrt::collection::lb::CMFTypeEnum c, FormatContext& ctx) {
-      std::string_view name = "Unknown";
-      switch (c) {
-      case ::vt::vrt::collection::lb::CMFTypeEnum::Original:
-        name = "Original";
-        break;
-      case ::vt::vrt::collection::lb::CMFTypeEnum::NormByMax:
-        name = "NormByMax";
-        break;
-      case ::vt::vrt::collection::lb::CMFTypeEnum::NormBySelf:
-        name = "NormBySelf";
-        break;
-      case ::vt::vrt::collection::lb::CMFTypeEnum::NormByMaxExcludeIneligible:
-        name = "NormByMaxExcludeIneligible";
-        break;
-      }
-      return formatter<string_view>::format(name, ctx);
-    }
-  };
-
-  // Specialize fmt::formatter for KnowledgeEnum
-  template <>
-  struct formatter<::vt::vrt::collection::lb::KnowledgeEnum>
-    : formatter<std::string_view> {
-    template <typename FormatContext>
-    auto
-    format(::vt::vrt::collection::lb::KnowledgeEnum c, FormatContext& ctx) {
-      std::string_view name = "Unknown";
-      switch (c) {
-      case ::vt::vrt::collection::lb::KnowledgeEnum::UserDefined:
-        name = "UserDefined";
-        break;
-      case ::vt::vrt::collection::lb::KnowledgeEnum::Complete:
-        name = "Complete";
-        break;
-      case ::vt::vrt::collection::lb::KnowledgeEnum::Log:
-        name = "Log";
-        break;
-      }
-      return formatter<string_view>::format(name, ctx);
-    }
-  };
-
-  // Specialize fmt::formatter for KnowledgeEnum
-  template <>
-  struct formatter<::vt::vrt::collection::lb::InformTypeEnum>
-    : formatter<std::string_view> {
-    template <typename FormatContext>
-    auto
-    format(::vt::vrt::collection::lb::InformTypeEnum c, FormatContext& ctx) {
-      std::string_view name = "Unknown";
-      switch (c) {
-      case ::vt::vrt::collection::lb::InformTypeEnum::SyncInform:
-        name = "SyncInform";
-        break;
-      case ::vt::vrt::collection::lb::InformTypeEnum::AsyncInform:
-        name = "AsyncInform";
-        break;
-      }
-      return formatter<string_view>::format(name, ctx);
-    }
-  };
-} // VT_FMT_NAMESPACE
-
 #endif /*INCLUDED_VT_VRT_COLLECTION_BALANCE_TEMPEREDLB_TEMPERED_ENUMS_H*/
diff --git a/tests/unit/lb/test_lbargs_enum_conv.nompi.cc b/tests/unit/lb/test_lbargs_enum_conv.nompi.cc
index c5658660d2..f6775cde10 100644
--- a/tests/unit/lb/test_lbargs_enum_conv.nompi.cc
+++ b/tests/unit/lb/test_lbargs_enum_conv.nompi.cc
@@ -148,7 +148,7 @@ TEST_F(TestLBArgsEnumConverter, test_enum_converter_config) {
 
 }}} // end namespace vt::tests::unit
 
-VT_FMT_NAMESPACE {
+VT_FMT_NAMESPACE_BEGIN
   template <>
   struct formatter<::vt::tests::unit::DummyEnum> : formatter<std::string_view> {
     template <typename FormatContext>
@@ -168,4 +168,4 @@ VT_FMT_NAMESPACE {
       return formatter<string_view>::format(name, ctx);
     }
   };
-} // VT_FMT_NAMESPACE
+VT_FMT_NAMESPACE_END