diff --git a/gnu/tests/install.scm b/gnu/tests/install.scm
index 4764ffffde..72e5523942 100644
--- a/gnu/tests/install.scm
+++ b/gnu/tests/install.scm
@@ -149,7 +149,7 @@ export GUIX_BUILD_OPTIONS=--no-grafts
 guix build isc-dhcp
 parted --script /dev/vdb mklabel gpt \\
   mkpart primary ext2 1M 3M \\
-  mkpart primary ext2 3M 1G \\
+  mkpart primary ext2 3M 1.2G \\
   set 1 boot on \\
   set 1 bios_grub on
 mkfs.ext4 -L my-root /dev/vdb2
@@ -174,7 +174,7 @@ guix --version
 export GUIX_BUILD_OPTIONS=--no-grafts
 guix build isc-dhcp
 parted --script /dev/vdb mklabel gpt \\
-  mkpart ext2 1M 1G \\
+  mkpart ext2 1M 1.2G \\
   set 1 legacy_boot on
 mkfs.ext4 -L my-root -O '^64bit' /dev/vdb1
 mount /dev/vdb1 /mnt
@@ -377,7 +377,7 @@ export GUIX_BUILD_OPTIONS=--no-grafts
 guix build isc-dhcp
 parted --script /dev/vda mklabel gpt \\
   mkpart primary ext2 1M 3M \\
-  mkpart primary ext2 3M 1G \\
+  mkpart primary ext2 3M 1.2G \\
   set 1 boot on \\
   set 1 bios_grub on
 mkfs.ext4 -L my-root /dev/vda2
@@ -510,7 +510,7 @@ guix build isc-dhcp
 parted --script /dev/vdb mklabel gpt \\
   mkpart primary ext2 1M 3M \\
   mkpart primary ext2 3M 100M \\
-  mkpart primary ext2 100M 1G \\
+  mkpart primary ext2 100M 1.2G \\
   set 1 boot on \\
   set 1 bios_grub on
 mkfs.ext4 -L root-fs /dev/vdb2
@@ -676,7 +676,7 @@ export GUIX_BUILD_OPTIONS=--no-grafts
 ls -l /run/current-system/gc-roots
 parted --script /dev/vdb mklabel gpt \\
   mkpart primary ext2 1M 3M \\
-  mkpart primary ext2 3M 1G \\
+  mkpart primary ext2 3M 1.2G \\
   set 1 boot on \\
   set 1 bios_grub on
 echo -n thepassphrase | \\