diff --git a/src/config_parser.cpp b/src/config_parser.cpp
index 8c84e95..e73c889 100644
--- a/src/config_parser.cpp
+++ b/src/config_parser.cpp
@@ -1,7 +1,5 @@
 #include "config_parser.hpp"
 
-#include <fmt/format.h>
-
 #include <stdplus/exception.hpp>
 #include <stdplus/fd/atomic.hpp>
 #include <stdplus/fd/create.hpp>
@@ -9,6 +7,7 @@
 #include <stdplus/fd/line.hpp>
 #include <stdplus/str/cat.hpp>
 
+#include <format>
 #include <functional>
 #include <iterator>
 #include <stdexcept>
@@ -164,7 +163,7 @@
         auto cpos = line.find(']');
         if (cpos == line.npos)
         {
-            warnings.emplace_back(fmt::format("{}:{}: Section missing ]",
+            warnings.emplace_back(std::format("{}:{}: Section missing ]",
                                               filename.get().native(), lineno));
         }
         else
@@ -174,7 +173,7 @@
                 if (!isspace(c))
                 {
                     warnings.emplace_back(
-                        fmt::format("{}:{}: Characters outside section name",
+                        std::format("{}:{}: Characters outside section name",
                                     filename.get().native(), lineno));
                     break;
                 }
@@ -196,7 +195,7 @@
         std::vector<std::string> new_warnings;
         if (epos == line.npos)
         {
-            new_warnings.emplace_back(fmt::format(
+            new_warnings.emplace_back(std::format(
                 "{}:{}: KV missing `=`", filename.get().native(), lineno));
         }
         auto k = line.substr(0, epos);
@@ -204,7 +203,7 @@
         if (section == nullptr)
         {
             new_warnings.emplace_back(
-                fmt::format("{}:{}: Key `{}` missing section",
+                std::format("{}:{}: Key `{}` missing section",
                             filename.get().native(), lineno, k));
         }
         if (!new_warnings.empty())
@@ -270,7 +269,7 @@
         fileExists = false;
         // TODO: Pass exceptions once callers can handle them
         parse.warnings.emplace_back(
-            fmt::format("{}: Open error: {}", filename.native(), e.what()));
+            std::format("{}: Open error: {}", filename.native(), e.what()));
     }
 
     this->map = std::move(parse.map);
diff --git a/src/ethernet_interface.cpp b/src/ethernet_interface.cpp
index 11485b9..fdd01c2 100644
--- a/src/ethernet_interface.cpp
+++ b/src/ethernet_interface.cpp
@@ -6,7 +6,6 @@
 #include "system_queries.hpp"
 #include "util.hpp"
 
-#include <fmt/format.h>
 #include <linux/rtnetlink.h>
 #include <net/if.h>
 #include <net/if_arp.h>
@@ -20,6 +19,7 @@
 
 #include <algorithm>
 #include <filesystem>
+#include <format>
 #include <string>
 #include <unordered_map>
 #include <variant>
@@ -527,7 +527,7 @@
 ServerList EthernetInterface::getNameServerFromResolvd()
 {
     ServerList servers;
-    auto OBJ_PATH = fmt::format("{}{}", RESOLVED_SERVICE_PATH, ifIdx);
+    auto OBJ_PATH = std::format("{}{}", RESOLVED_SERVICE_PATH, ifIdx);
 
     /*
       The DNS property under org.freedesktop.resolve1.Link interface contains
@@ -704,9 +704,7 @@
             {
                 if (originIsManuallyAssigned(addr.second->origin()))
                 {
-                    address.emplace_back(
-                        fmt::format("{}/{}", addr.second->address(),
-                                    addr.second->prefixLength()));
+                    address.emplace_back(stdplus::toStr(addr.first));
                 }
             }
         }
diff --git a/src/netlink.cpp b/src/netlink.cpp
index 69ea5c6..eccf039 100644
--- a/src/netlink.cpp
+++ b/src/netlink.cpp
@@ -1,6 +1,5 @@
 #include "netlink.hpp"
 
-#include <fmt/format.h>
 #include <linux/netlink.h>
 #include <linux/rtnetlink.h>
 
@@ -9,6 +8,7 @@
 #include <stdplus/raw.hpp>
 
 #include <array>
+#include <format>
 #include <stdexcept>
 #include <system_error>
 
@@ -30,13 +30,13 @@
     if (hdr.nlmsg_len < sizeof(hdr))
     {
         throw std::runtime_error(
-            fmt::format("nlmsg length shorter than header: {} < {}",
+            std::format("nlmsg length shorter than header: {} < {}",
                         hdr.nlmsg_len, sizeof(hdr)));
     }
     if (msgs.size() < hdr.nlmsg_len)
     {
         throw std::runtime_error(
-            fmt::format("not enough message for nlmsg: {} < {}", msgs.size(),
+            std::format("not enough message for nlmsg: {} < {}", msgs.size(),
                         hdr.nlmsg_len));
     }
     auto msg = msgs.substr(NLMSG_HDRLEN, hdr.nlmsg_len - NLMSG_HDRLEN);
@@ -185,13 +185,13 @@
     const auto& hdr = stdplus::raw::refFrom<rtattr, Aligned>(data);
     if (hdr.rta_len < RTA_LENGTH(0))
     {
-        throw std::runtime_error(fmt::format(
+        throw std::runtime_error(std::format(
             "rtattr shorter than header: {} < {}", hdr.rta_len, RTA_LENGTH(0)));
     }
     if (data.size() < hdr.rta_len)
     {
         throw std::runtime_error(
-            fmt::format("not enough message for rtattr: {} < {}", data.size(),
+            std::format("not enough message for rtattr: {} < {}", data.size(),
                         hdr.rta_len));
     }
     auto attr = data.substr(RTA_LENGTH(0), hdr.rta_len - RTA_LENGTH(0));
diff --git a/src/network_manager.cpp b/src/network_manager.cpp
index b14c106..47a528f 100644
--- a/src/network_manager.cpp
+++ b/src/network_manager.cpp
@@ -17,9 +17,11 @@
 #include <stdplus/numeric/str.hpp>
 #include <stdplus/pinned.hpp>
 #include <stdplus/print.hpp>
+#include <stdplus/str/cat.hpp>
 #include <xyz/openbmc_project/Common/error.hpp>
 
 #include <filesystem>
+#include <format>
 
 namespace phosphor
 {
@@ -29,6 +31,7 @@
 using namespace phosphor::logging;
 using namespace sdbusplus::xyz::openbmc_project::Common::Error;
 using Argument = xyz::openbmc_project::Common::InvalidArgument;
+using std::literals::string_view_literals::operator""sv;
 
 static constexpr const char enabledMatch[] =
     "type='signal',sender='org.freedesktop.network1',path_namespace='/org/"
@@ -134,7 +137,9 @@
     for (const auto& link : links)
     {
         unsigned ifidx = std::get<0>(link);
-        auto obj = fmt::format("/org/freedesktop/network1/link/_3{}", ifidx);
+        stdplus::ToStrHandle<stdplus::IntToStr<10, unsigned>> tsh;
+        auto obj = stdplus::strCat("/org/freedesktop/network1/link/_3"sv,
+                                   tsh(ifidx));
         auto req =
             bus.get().new_method_call("org.freedesktop.network1", obj.c_str(),
                                       "org.freedesktop.DBus.Properties", "Get");
@@ -297,7 +302,7 @@
     else if (!ignoredIntf.contains(info.ifidx))
     {
         throw std::runtime_error(
-            fmt::format("Interface `{}` not found for addr", info.ifidx));
+            std::format("Interface `{}` not found for addr", info.ifidx));
     }
 }
 
@@ -331,7 +336,7 @@
     else if (!ignoredIntf.contains(info.ifidx))
     {
         throw std::runtime_error(
-            fmt::format("Interface `{}` not found for neigh", info.ifidx));
+            std::format("Interface `{}` not found for neigh", info.ifidx));
     }
 }
 
diff --git a/src/system_queries.cpp b/src/system_queries.cpp
index f58493a..17dd09a 100644
--- a/src/system_queries.cpp
+++ b/src/system_queries.cpp
@@ -2,7 +2,6 @@
 
 #include "netlink.hpp"
 
-#include <fmt/format.h>
 #include <linux/ethtool.h>
 #include <linux/rtnetlink.h>
 #include <linux/sockios.h>
@@ -14,6 +13,7 @@
 #include <stdplus/util/cexec.hpp>
 
 #include <algorithm>
+#include <format>
 #include <optional>
 #include <stdexcept>
 #include <string_view>
@@ -126,7 +126,7 @@
             err = netlink::extractRtData<nlmsgerr>(data).error;
         }
         throw std::runtime_error(
-            fmt::format("Failed to delete `{}`: {}", idx, strerror(err)));
+            std::format("Failed to delete `{}`: {}", idx, strerror(err)));
     });
 }
 
diff --git a/test/test_config_parser.cpp b/test/test_config_parser.cpp
index d666502..692cabd 100644
--- a/test/test_config_parser.cpp
+++ b/test/test_config_parser.cpp
@@ -8,6 +8,7 @@
 #include <xyz/openbmc_project/Common/error.hpp>
 
 #include <exception>
+#include <format>
 #include <fstream>
 #include <stdexcept>
 
@@ -76,7 +77,7 @@
 class TestConfigParser : public stdplus::gtest::TestWithTmp
 {
   public:
-    std::string filename = fmt::format("{}/eth0.network", CaseTmpDir());
+    std::string filename = std::format("{}/eth0.network", CaseTmpDir());
     Parser parser;
 
     void WriteSampleFile()
@@ -180,7 +181,7 @@
 TEST_F(TestConfigParser, Perf)
 {
     GTEST_SKIP();
-    stdplus::fd::AtomicWriter file(fmt::format("{}/tmp.XXXXXX", CaseTmpDir()),
+    stdplus::fd::AtomicWriter file(std::format("{}/tmp.XXXXXX", CaseTmpDir()),
                                    0600);
     stdplus::fd::FormatBuffer out(file);
     std::string obj(500, 'a');
diff --git a/test/test_netlink.cpp b/test/test_netlink.cpp
index f256c3a..8686b7b 100644
--- a/test/test_netlink.cpp
+++ b/test/test_netlink.cpp
@@ -8,6 +8,7 @@
 #include <stdplus/raw.hpp>
 
 #include <cstring>
+#include <format>
 #include <stdexcept>
 #include <string_view>
 
@@ -302,7 +303,7 @@
             system::mock_addIF(InterfaceInfo{.type = 1u,
                                              .idx = i + 1u,
                                              .flags = 0,
-                                             .name = fmt::format("eth{}", i)});
+                                             .name = std::format("eth{}", i)});
         }
 
         size_t cbCalls = 0;