diff --git a/config/cardpick.go b/config/cardpick.go
index ab3f4ef0..33124291 100644
--- a/config/cardpick.go
+++ b/config/cardpick.go
@@ -2,12 +2,17 @@ package config
 
 import (
 	"errors"
-	"fmt"
 	"strconv"
 
 	"github.com/vinegarhq/vinegar/sysinfo"
 )
 
+var (
+	ErrOpenGLBlind = errors.New("opengl is not capable of choosing the right gpu, it must be explicitly defined")
+	ErrNoCardFound = errors.New("gpu not found")
+	ErrBadGpuIndex = errors.New("gpu index cannot be negative")
+)
+
 func (b *Binary) pickCard() error {
 	if b.ForcedGpu == "" {
 		return nil
@@ -38,7 +43,7 @@ func (b *Binary) pickCard() error {
 		vk := b.Dxvk || b.Renderer == "Vulkan"
 
 		if n != 2 && (!vk && n != 1) {
-			return fmt.Errorf("opengl is not capable of choosing the right gpu, it must be explicitly defined")
+			return ErrOpenGLBlind
 		}
 
 		if n != 2 {
@@ -51,11 +56,11 @@ func (b *Binary) pickCard() error {
 	}
 
 	if idx < 0 {
-		return errors.New("gpu index cannot be negative")
+		return ErrBadGpuIndex
 	}
 
 	if n < idx+1 {
-		return errors.New("gpu not found")
+		return ErrNoCardFound
 	}
 
 	b.Env.Set("MESA_VK_DEVICE_SELECT_FORCE_DEFAULT_DEVICE", "1")
diff --git a/config/cardpick_test.go b/config/cardpick_test.go
new file mode 100644
index 00000000..812b8737
--- /dev/null
+++ b/config/cardpick_test.go
@@ -0,0 +1,83 @@
+package config
+
+import (
+	"errors"
+	"strconv"
+	"testing"
+	"github.com/vinegarhq/vinegar/sysinfo"
+)
+
+func TestCard(t *testing.T) {
+	sysinfo.Cards = []sysinfo.Card{}
+	b := Binary{
+		ForcedGpu: "meow",
+		Env: Environment{},
+	}
+
+	if err := b.pickCard(); !errors.Is(err, strconv.ErrSyntax) {
+		t.Fatal("expected to not handle string gpu")
+	}
+
+	b.ForcedGpu = "1"
+	if err := b.pickCard(); !errors.Is(err, ErrNoCardFound) {
+		t.Fatal("expected to handle no gpu found")
+	}
+
+	b.ForcedGpu = "-1"
+	if err := b.pickCard(); !errors.Is(err, ErrBadGpuIndex) {
+		t.Fatal("expected to not handle negative gpu index")
+	}
+}
+
+func TestPRIMECard(t *testing.T) {
+	b := Binary{
+		ForcedGpu: "integrated",
+		Env: Environment{},
+	}
+	sysinfo.Cards = []sysinfo.Card{
+		{
+			Driver: "i915",
+			Embedded: true,
+		},
+	}
+
+	if err := b.pickCard(); err != nil {
+		t.Fatal(err)
+	}
+
+	if _, ok := b.Env["DRI_PRIME"]; ok {
+		t.Fatal("expected no change")
+	}
+
+	sysinfo.Cards = append(sysinfo.Cards, sysinfo.Card{
+		Driver: "nvidia",
+		Embedded: false,
+	})
+
+	if err := b.pickCard(); err != nil {
+		t.Fatal(err)
+	}
+
+	if v := b.Env["DRI_PRIME"]; v != "0" {
+		t.Fatal("expected change in prime index")
+	}
+
+	if v := b.Env["__GLX_VENDOR_LIBRARY_NAME"]; v != "mesa" {
+		t.Fatal("expected glx vendor to be mesa")
+	}
+
+	b.ForcedGpu = "prime-discrete"
+	delete(b.Env, "DRI_PRIME")
+	delete(b.Env, "__GLX_VENDOR_LIBRARY_NAME")
+	if err := b.pickCard(); err != nil {
+		t.Fatal(err)
+	}
+
+	if v := b.Env["DRI_PRIME"]; v != "1" {
+		t.Fatal("expected change in descrete index")
+	}
+
+	if v := b.Env["__GLX_VENDOR_LIBRARY_NAME"]; v != "nvidia" {
+		t.Fatal("expected glx vendor to be nvidia")
+	}
+}
\ No newline at end of file