diff --git a/pkgs/development/ocaml-modules/tcpip/default.nix b/pkgs/development/ocaml-modules/tcpip/default.nix
index 6e639f984cb..80fa01066f1 100644
--- a/pkgs/development/ocaml-modules/tcpip/default.nix
+++ b/pkgs/development/ocaml-modules/tcpip/default.nix
@@ -1,5 +1,5 @@
 { lib, buildDunePackage, fetchurl
-, bisect_ppx, ppx_cstruct, pkg-config
+, bisect_ppx, ppx_cstruct
 , rresult, cstruct, cstruct-lwt, mirage-net, mirage-clock
 , mirage-random, mirage-stack, mirage-protocols, mirage-time
 , ipaddr, macaddr, macaddr-cstruct, mirage-profile, fmt
@@ -11,23 +11,18 @@
 
 buildDunePackage rec {
   pname = "tcpip";
-  version = "6.1.0";
+  version = "6.0.0";
 
   useDune2 = true;
 
   src = fetchurl {
     url = "https://github.com/mirage/mirage-${pname}/releases/download/v${version}/${pname}-v${version}.tbz";
-    sha256 = "e81c98a6e80e05f9fa4e5fbee50e6c247f6011254c7b1d9a0e58bae318c1f0c8";
+    sha256 = "0wbrs8jz1vw3zdrqmqcwawxh4yhc2gy30rw7gz4w116cblkvnb8s";
   };
 
-  patches = [
-    ./no-opam-pkg-config-path.patch
-  ];
-
   nativeBuildInputs = [
     bisect_ppx
     ppx_cstruct
-    pkg-config
   ];
 
   propagatedBuildInputs = [
diff --git a/pkgs/development/ocaml-modules/tcpip/no-opam-pkg-config-path.patch b/pkgs/development/ocaml-modules/tcpip/no-opam-pkg-config-path.patch
deleted file mode 100644
index a7e9155ce5a..00000000000
--- a/pkgs/development/ocaml-modules/tcpip/no-opam-pkg-config-path.patch
+++ /dev/null
@@ -1,21 +0,0 @@
-diff --git a/freestanding/Makefile b/freestanding/Makefile
-index f22d220d..4bb3ac57 100644
---- a/freestanding/Makefile
-+++ b/freestanding/Makefile
-@@ -1,6 +1,4 @@
--PKG_CONFIG_PATH := $(shell opam config var prefix)/lib/pkgconfig
--
--EXISTS := $(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) pkg-config --exists ocaml-freestanding; echo $$?)
-+EXISTS := $(shell pkg-config --exists ocaml-freestanding; echo $$?)
- 
- .PHONY: all clean
- all: libtcpip_freestanding_stubs.a
-@@ -10,7 +8,7 @@ libtcpip_freestanding_stubs.a:
- 	touch $@
- else
- CC ?= cc
--FREESTANDING_CFLAGS := $(shell PKG_CONFIG_PATH=$(PKG_CONFIG_PATH) pkg-config --cflags ocaml-freestanding)
-+FREESTANDING_CFLAGS := $(shell pkg-config --cflags ocaml-freestanding)
- CFLAGS := $(FREESTANDING_CFLAGS)
- 
- OBJS=checksum_stubs.o