diff --git a/pkgs/os-specific/linux/kernel/linux-rt-5.10.nix b/pkgs/os-specific/linux/kernel/linux-rt-5.10.nix
index c3c11fd7cd94..85fb35f38dbf 100644
--- a/pkgs/os-specific/linux/kernel/linux-rt-5.10.nix
+++ b/pkgs/os-specific/linux/kernel/linux-rt-5.10.nix
@@ -25,7 +25,7 @@ buildLinux (
 
     src = fetchurl {
       url = "mirror://kernel/linux/kernel/v5.x/linux-${kversion}.tar.xz";
-      sha256 = "17wxs8i8vd5ivv99ra0sri3wmkw5c22wsaw8nf1xcvys2kmpa7hk";
+      hash = "sha256-Ex516xTab9aDs4grzYVghc/KR8waqJzS3rG0jSLSnZ8=";
     };
 
     kernelPatches =
@@ -34,7 +34,7 @@ buildLinux (
           name = "rt";
           patch = fetchurl {
             url = "mirror://kernel/linux/kernel/projects/rt/${branch}/older/patch-${version}.patch.xz";
-            sha256 = "1nqdshpcf775cmb1kqcq939b7qx6wsy91pf0l0vsd3rdpixidzyk";
+            hash = "sha256-0/8We7wtj6Y3oMDdkLzmpuOz0kiY4RlWZeUcxy7UDds=";
           };
         };
       in
diff --git a/pkgs/os-specific/linux/kernel/linux-rt-5.15.nix b/pkgs/os-specific/linux/kernel/linux-rt-5.15.nix
index 822d06217b1e..a694cf30d818 100644
--- a/pkgs/os-specific/linux/kernel/linux-rt-5.15.nix
+++ b/pkgs/os-specific/linux/kernel/linux-rt-5.15.nix
@@ -29,7 +29,7 @@ buildLinux (
 
     src = fetchurl {
       url = "mirror://kernel/linux/kernel/v5.x/linux-${kversion}.tar.xz";
-      sha256 = "0hd4p76qv29zlr0iik4j9y9qynyqisk6bgfiqcwkk7gr6bf81l13";
+      hash = "sha256-I9CA3DL5nTk5w9G9ZaaO2FuPk0+SzBhBpj+Jjc25pEE=";
     };
 
     kernelPatches =
@@ -38,7 +38,7 @@ buildLinux (
           name = "rt";
           patch = fetchurl {
             url = "mirror://kernel/linux/kernel/projects/rt/${branch}/older/patch-${version}.patch.xz";
-            sha256 = "15n1l3b0yq7hl2zady3s3a3zym82clyycvf5icavvd68758sdp25";
+            hash = "sha256-RdymUTnItL0Vi8Vt5j1lAlX/hxp6+Ka+oPBgD9agwZY=";
           };
         };
       in
diff --git a/pkgs/os-specific/linux/kernel/linux-rt-6.1.nix b/pkgs/os-specific/linux/kernel/linux-rt-6.1.nix
index 508da7ec98cd..25ee763a96b2 100644
--- a/pkgs/os-specific/linux/kernel/linux-rt-6.1.nix
+++ b/pkgs/os-specific/linux/kernel/linux-rt-6.1.nix
@@ -29,7 +29,7 @@ buildLinux (
 
     src = fetchurl {
       url = "mirror://kernel/linux/kernel/v6.x/linux-${kversion}.tar.xz";
-      sha256 = "13i2l04pmba7dksz2p5kwxgr5bydc5lp7284d4wfsnjf425i9fyl";
+      hash = "sha256-1LsUiyBOWu04aQSJc2lhza+SX+ezXPH1bEetegmgIo4=";
     };
 
     kernelPatches =
@@ -38,7 +38,7 @@ buildLinux (
           name = "rt";
           patch = fetchurl {
             url = "mirror://kernel/linux/kernel/projects/rt/${branch}/older/patch-${version}.patch.xz";
-            sha256 = "1smah5wa4lrgb13li025lpj80yxay4g13m7c4i09whxcgxhc294k";
+            hash = "sha256-kyTBYH+sQ55AJOzUER7xqnuA5KVFgEhHWC9ToniBquo=";
           };
         };
       in
diff --git a/pkgs/os-specific/linux/kernel/linux-rt-6.6.nix b/pkgs/os-specific/linux/kernel/linux-rt-6.6.nix
index 5ce2e345bc97..d6783e3f3fe4 100644
--- a/pkgs/os-specific/linux/kernel/linux-rt-6.6.nix
+++ b/pkgs/os-specific/linux/kernel/linux-rt-6.6.nix
@@ -29,7 +29,7 @@ buildLinux (
 
     src = fetchurl {
       url = "mirror://kernel/linux/kernel/v6.x/linux-${kversion}.tar.xz";
-      sha256 = "08la2f8w5w2x0l9nmvzsmbwa951xyshhvdhwwhfyjmka66zr4zbc";
+      hash = "sha256-bH2SvzFqVukd5By2DaH2PZSk+Kr672oTBV3wwpETiiI=";
     };
 
     kernelPatches =
@@ -38,7 +38,7 @@ buildLinux (
           name = "rt";
           patch = fetchurl {
             url = "mirror://kernel/linux/kernel/projects/rt/${branch}/older/patch-${version}.patch.xz";
-            sha256 = "01z2dwl54hfqfyc8xmlz6kaw522s55jsdrdw31pjnzkn6rxf7zbf";
+            hash = "sha256-bv3jejZ2fitvGLzlpmUpWojC1TSf1o6Yd9hBUihv4gc=";
           };
         };
       in
diff --git a/pkgs/os-specific/linux/kernel/update-rt.sh b/pkgs/os-specific/linux/kernel/update-rt.sh
index a9e0577fae92..38221e97716f 100755
--- a/pkgs/os-specific/linux/kernel/update-rt.sh
+++ b/pkgs/os-specific/linux/kernel/update-rt.sh
@@ -55,8 +55,8 @@ update-if-needed() {
         echo "$nixattr: $cur (up-to-date)"
         return
     fi
-    khash=$(nix-prefetch-url "$mirror/v${major}.x/linux-${kversion}.tar.xz")
-    phash=$(nix-prefetch-url "$mirror/projects/rt/${branch}/older/patch-${new}.patch.xz")
+    khash=$(nix-prefetch-url "$mirror/v${major}.x/linux-${kversion}.tar.xz" | nix-hash --type sha256 --to-sri)
+    phash=$(nix-prefetch-url "$mirror/projects/rt/${branch}/older/patch-${new}.patch.xz" | nix-hash --type sha256 --to-sri)
     if [ "$cur" ]; then
         msg="$nixattr: $cur -> $new"
     else
@@ -69,8 +69,8 @@ update-if-needed() {
     sed -i "$file" \
         -e "s/$cur/$new/" \
         -e "s|kernel/v[0-9]*|kernel/v$major|" \
-        -e "1,/.patch.xz/ s/sha256 = .*/sha256 = \"$khash\";/" \
-        -e "1,/.patch.xz/! s/sha256 = .*/sha256 = \"$phash\";/"
+        -e "1,/.patch.xz/ s|hash = .*|hash = \"$khash\";|" \
+        -e "1,/.patch.xz/! s|hash = .*|hash = \"$phash\";|"
     if [ "${COMMIT:-}" ]; then
         git add "$file"
         git commit -m "$msg"