diff --git a/src/libstore/unix/build/linux-derivation-builder.cc b/src/libstore/unix/build/linux-derivation-builder.cc
index 35730644b..f6e910d08 100644
--- a/src/libstore/unix/build/linux-derivation-builder.cc
+++ b/src/libstore/unix/build/linux-derivation-builder.cc
@@ -3,6 +3,7 @@
 #  include "nix/store/personality.hh"
 #  include "nix/util/cgroup.hh"
 #  include "nix/util/linux-namespaces.hh"
+#  include "nix/util/logging.hh"
 #  include "linux/fchmodat2-compat.hh"
 
 #  include <sys/ioctl.h>
@@ -505,8 +506,16 @@ struct ChrootLinuxDerivationBuilder : ChrootDerivationBuilder, LinuxDerivationBu
             createDirs(chrootRootDir + "/dev/shm");
             createDirs(chrootRootDir + "/dev/pts");
             ss.push_back("/dev/full");
-            if (systemFeatures.count("kvm") && pathExists("/dev/kvm"))
-                ss.push_back("/dev/kvm");
+            if (systemFeatures.count("kvm")) {
+                if (pathExists("/dev/kvm")) {
+                    ss.push_back("/dev/kvm");
+                } else {
+                    warn(
+                        "KVM is enabled in system-features but /dev/kvm is not available. "
+                        "QEMU builds may fall back to slow emulation. "
+                        "Consider removing 'kvm' from system-features in nix.conf if KVM is not supported on this system.");
+                }
+            }
             ss.push_back("/dev/null");
             ss.push_back("/dev/random");
             ss.push_back("/dev/tty");