diff --git a/.changelog/25523.txt b/.changelog/25523.txt
new file mode 100644
index 000000000..2734b8ba0
--- /dev/null
+++ b/.changelog/25523.txt
@@ -0,0 +1,3 @@
+```release-note:improvement
+client: Fixed a bug where JSON formatted logs would not show the requested and overlapping cores when failing to reserve cores
+```
diff --git a/client/lib/cgroupslib/partition_linux.go b/client/lib/cgroupslib/partition_linux.go
index a3bfe294a..ff36c21b5 100644
--- a/client/lib/cgroupslib/partition_linux.go
+++ b/client/lib/cgroupslib/partition_linux.go
@@ -85,7 +85,7 @@ func (p *partition) Reserve(cores *idset.Set[hw.CoreID]) error {
 	overlappingCores := p.reserve.Intersect(usableCores)
 	if overlappingCores.Size() > 0 {
 		// COMPAT: prior to Nomad 1.9.X this would silently happen, this should probably return an error instead
-		p.log.Warn("Unable to exclusively reserve the requested cores", "cores", cores, "overlapping_cores", overlappingCores)
+		p.log.Warn("Unable to exclusively reserve the requested cores", "cores", cores.Slice(), "overlapping_cores", overlappingCores.Slice())
 	}
 
 	p.share.RemoveSet(cores)