diff --git a/nix/pkgs/prometheus-snmp-config/42c9b661cda04ca33c697fa75e1c0a98d8214233.patch b/nix/pkgs/prometheus-snmp-config/42c9b661cda04ca33c697fa75e1c0a98d8214233.patch
new file mode 100644
index 0000000000..fb74d1622e
--- /dev/null
+++ b/nix/pkgs/prometheus-snmp-config/42c9b661cda04ca33c697fa75e1c0a98d8214233.patch
@@ -0,0 +1,13 @@
+diff --git a/generator/Makefile b/generator/Makefile
+index 789e96c..2474669 100644
+--- a/generator/Makefile
++++ b/generator/Makefile
+@@ -20,7 +20,7 @@ DOCKER_IMAGE_NAME ?= snmp-generator
+ DOCKER_IMAGE_TAG  ?= $(subst /,-,$(shell git rev-parse --abbrev-ref HEAD))
+ DOCKER_REPO       ?= prom
+ 
+-APC_URL           := https://download.schneider-electric.com/files?p_enDocType=Firmware&p_File_Name=powernet446.mib&p_Doc_Ref=APC_POWERNETMIB_446_EN
++APC_URL           := https://download.schneider-electric.com/files?p_enDocType=Firmware&p_File_Name=powernet449.mib&p_Doc_Ref=APC_POWERNETMIB_449_EN
+ ARISTA_URL        := https://www.arista.com/assets/data/docs/MIBS
+ CISCO_URL         := https://raw.githubusercontent.com/cisco/cisco-mibs/2d465cce2de4e67a3561d8e41e4c99b597558d4b/v2
+ IANA_CHARSET_URL  := https://www.iana.org/assignments/ianacharset-mib/ianacharset-mib
diff --git a/nix/pkgs/prometheus-snmp-config/default.nix b/nix/pkgs/prometheus-snmp-config/default.nix
index 1b17aca21c..3eb444c9dc 100644
--- a/nix/pkgs/prometheus-snmp-config/default.nix
+++ b/nix/pkgs/prometheus-snmp-config/default.nix
@@ -24,7 +24,7 @@ let
     version = "lukegb-${prometheus-snmp-exporter.version}";
 
     outputHashMode = "recursive";
-    outputHash = "sha256:0i2cn5yxb2rnkg91wjmyzd5g2y3cr5yhfkbr9715kw5qk4rf73a0";
+    outputHash = "sha256:1bsksj21ffzr5b53h2bxk10n8zyasxwxvbfmzrs0x3pbpfmf9bxx";
 
     buildInputs = [
       curl
@@ -44,6 +44,11 @@ let
       cp $src/generator/Makefile $NIX_BUILD_TOP/build/Makefile
     '';
 
+    patchPhase = ''
+      sed -i $NIX_BUILD_TOP/build/Makefile -e 's,powernet446,powernet451,g' -e 's,POWERNETMIB_446,POWERNETMIB_451,g'
+      cat $NIX_BUILD_TOP/build/Makefile
+    '';
+
     buildPhase = ''
       pushd $NIX_BUILD_TOP/build
       mkdir mibs