diff --git a/hal/src/main/native/athena/FRCDriverStation.cpp b/hal/src/main/native/athena/FRCDriverStation.cpp
index bce631ff54..3d5f207aa9 100644
--- a/hal/src/main/native/athena/FRCDriverStation.cpp
+++ b/hal/src/main/native/athena/FRCDriverStation.cpp
@@ -204,12 +204,12 @@ int32_t HAL_SendError(HAL_Bool isError, int32_t errorCode, HAL_Bool isLVCode,
     if (printMsg) {
       fmt::memory_buffer buf;
       if (location && location[0] != '\0') {
-        fmt::format_to(buf, "{} at {}: ", isError ? "Error" : "Warning",
-                       location);
+        fmt::format_to(fmt::appender{buf},
+                       "{} at {}: ", isError ? "Error" : "Warning", location);
       }
-      fmt::format_to(buf, "{}\n", details);
+      fmt::format_to(fmt::appender{buf}, "{}\n", details);
       if (callStack && callStack[0] != '\0') {
-        fmt::format_to(buf, "{}\n", callStack);
+        fmt::format_to(fmt::appender{buf}, "{}\n", callStack);
       }
       std::fwrite(buf.data(), buf.size(), 1, stderr);
     }
diff --git a/hal/src/main/native/sim/DriverStation.cpp b/hal/src/main/native/sim/DriverStation.cpp
index d02319f93f..723cdacfa8 100644
--- a/hal/src/main/native/sim/DriverStation.cpp
+++ b/hal/src/main/native/sim/DriverStation.cpp
@@ -85,12 +85,12 @@ int32_t HAL_SendError(HAL_Bool isError, int32_t errorCode, HAL_Bool isLVCode,
     if (printMsg) {
       fmt::memory_buffer buf;
       if (location && location[0] != '\0') {
-        fmt::format_to(buf, "{} at {}: ", isError ? "Error" : "Warning",
-                       location);
+        fmt::format_to(fmt::appender{buf},
+                       "{} at {}: ", isError ? "Error" : "Warning", location);
       }
-      fmt::format_to(buf, "{}\n", details);
+      fmt::format_to(fmt::appender{buf}, "{}\n", details);
       if (callStack && callStack[0] != '\0') {
-        fmt::format_to(buf, "{}\n", callStack);
+        fmt::format_to(fmt::appender{buf}, "{}\n", callStack);
       }
       std::fwrite(buf.data(), buf.size(), 1, stderr);
     }
diff --git a/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp b/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp
index 017d0af2ed..cc519f5bad 100644
--- a/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp
+++ b/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp
@@ -93,7 +93,7 @@ NetworkTableEntry NetworkTable::GetEntry(std::string_view key) const {
   NT_Entry& entry = m_entries[key];
   if (entry == 0) {
     fmt::memory_buffer buf;
-    fmt::format_to(buf, "{}/{}", m_path, key);
+    fmt::format_to(fmt::appender{buf}, "{}/{}", m_path, key);
     entry = nt::GetEntry(m_inst, {buf.data(), buf.size()});
   }
   return NetworkTableEntry{entry};
diff --git a/wpilibc/src/main/native/cpp/Notifier.cpp b/wpilibc/src/main/native/cpp/Notifier.cpp
index df6e488482..441f7507c8 100644
--- a/wpilibc/src/main/native/cpp/Notifier.cpp
+++ b/wpilibc/src/main/native/cpp/Notifier.cpp
@@ -140,7 +140,7 @@ Notifier& Notifier::operator=(Notifier&& rhs) {
 
 void Notifier::SetName(std::string_view name) {
   fmt::memory_buffer buf;
-  fmt::format_to(buf, "{}", name);
+  fmt::format_to(fmt::appender{buf}, "{}", name);
   buf.push_back('\0');  // null terminate
   int32_t status = 0;
   HAL_SetNotifierName(m_notifier, buf.data(), &status);