diff --git a/tools/runner.py b/tools/runner.py
index a96627de..004bf46d 100644
--- a/tools/runner.py
+++ b/tools/runner.py
@@ -370,6 +370,7 @@ class QemuRunner(RunnerAbstract):
 
 		usb_adapters = None
 		pci_adapters = None
+		ram = 256
 
 		super().__init__(args)
 
@@ -400,11 +401,14 @@ class QemuRunner(RunnerAbstract):
 
 		kern_log = "ignore_loglevel" if "kernel" in args.verbose else "quiet"
 
+		if args.valgrind:
+			ram *= 2
+
 		qemu_cmdline = [
 			'qemu-system-x86_64',
 			'-machine', 'type=q35,accel=kvm:tcg',
 			'-nodefaults', '-no-user-config', '-monitor', 'none',
-			'-display', 'none', '-m', '256M', '-nographic', '-vga',
+			'-display', 'none', '-m', '%dM' % ram, '-nographic', '-vga',
 			'none', '-no-acpi', '-no-hpet',
 			'-no-reboot', '-fsdev',
 			'local,id=fsdev-root,path=/,readonly=on,security_model=none,multidevs=remap',