diff --git a/geo/osm2pgsql/patches/patch-src_output-flex_cpp b/geo/osm2pgsql/patches/patch-src_output-flex_cpp
new file mode 100644
index 00000000000..10b1da8f70c
--- /dev/null
+++ b/geo/osm2pgsql/patches/patch-src_output-flex_cpp
@@ -0,0 +1,15 @@
+fix build with fmt 8.1.1
+
+from https://github.com/openstreetmap/osm2pgsql/commit/a29d1fa6b105bfe385280b39ac3143f020ff241d
+Index: src/output-flex.cpp
+--- src/output-flex.cpp.orig
++++ src/output-flex.cpp
+@@ -636,7 +636,7 @@ void output_flex_t::write_column(
+         }
+     } else {
+         throw std::runtime_error{
+-            "Column type {} not implemented."_format(column.type())};
++            "Column type {} not implemented."_format(static_cast<uint8_t>(column.type()))};
+     }
+ 
+     lua_pop(lua_state(), 1);