diff --git a/nix/c-ares-cmake.nix b/nix/c-ares-cmake.nix
new file mode 100644
--- /dev/null
+++ b/nix/c-ares-cmake.nix
@@ -0,0 +1,26 @@
+{ lib, stdenv, c-ares, writeTextFile }:
+
+let
+  extension = if stdenv.hostPlatform.isStatic then ".a" else stdenv.hostPlatform.extensions.sharedLibrary;
+  buildType = if stdenv.hostPlatform.isStatic then "STATIC" else "SHARED";
+  buildTypeLower = if stdenv.hostPlatform.isStatic then "static" else "shared";
+in writeTextFile {
+  name = "c-ares-cmake-config";
+  destination = "/lib/cmake/c-ares/c-ares-config.cmake";
+  text = ''
+    set(c-ares_INCLUDE_DIR "${c-ares}/include")
+    set(c-ares_LIBRARY c-ares::cares)
+    add_library(c-ares::cares ${buildType} IMPORTED)
+    set_target_properties(c-ares::cares PROPERTIES
+      INTERFACE_INCLUDE_DIRECTORIES "${c-ares}/include"
+    )
+    set_property(TARGET c-ares::cares APPEND PROPERTY IMPORTED_CONFIGURATIONS RELEASE)
+    set_target_properties(c-ares::cares PROPERTIES
+      IMPORTED_LOCATION_RELEASE "${c-ares}/lib/libcares${extension}"
+      IMPORTED_SONAME_RELEASE "libcares${extension}"
+      )
+    add_library(c-ares::cares_${buildTypeLower} INTERFACE IMPORTED)
+    set_target_properties(c-ares::cares_${buildTypeLower} PROPERTIES INTERFACE_LINK_LIBRARIES "c-ares::cares")
+    set(c-ares_${buildType}_LIBRARY c-ares::cares_${buildTypeLower})
+  '';
+}
diff --git a/nix/dev-shell.nix b/nix/dev-shell.nix
--- a/nix/dev-shell.nix
+++ b/nix/dev-shell.nix
@@ -6,6 +6,7 @@
 , aws-sdk-cpp
 , better-prompt
 , boost
+, c-ares_cmake-config
 , cargo
 , cmake
 , cmake-format
@@ -65,6 +66,7 @@
 
     # Tunnelbroker + CMake
     amqp-cpp
+    c-ares_cmake-config
     cryptopp
     cmake
     cmake-format # linting
diff --git a/nix/overlay.nix b/nix/overlay.nix
--- a/nix/overlay.nix
+++ b/nix/overlay.nix
@@ -43,6 +43,11 @@
 
   better-prompt = prev.callPackage ./better-prompt.nix { };
 
+  # Vendored version of https://github.com/NixOS/nixpkgs/pull/191120
+  # and https://github.com/NixOS/nixpkgs/pull/191123
+  # Can remove after upstream PRs gets merged and nixos-unstable channel updates
+  c-ares_cmake-config = final.callPackage ./c-ares-cmake.nix { };
+
   protobuf_3_15_cmake = prev.callPackage ./protobuf_3_15.nix { };
 
   devShell = final.callPackage ./dev-shell.nix { };