diff --git a/internal/buildengine/build_go_test.go b/internal/buildengine/build_go_test.go
index 8f324379c6..5515ed3ac6 100644
--- a/internal/buildengine/build_go_test.go
+++ b/internal/buildengine/build_go_test.go
@@ -3,11 +3,14 @@ package buildengine
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 	"runtime"
 	"testing"
 
 	"github.com/alecthomas/assert/v2"
 
+	"github.com/otiai10/copy"
+
 	"github.com/TBD54566975/ftl/backend/schema"
 )
 
@@ -51,6 +54,16 @@ func TestGoModVersion(t *testing.T) {
 	if testing.Short() {
 		t.SkipNow()
 	}
+	tmpDir, err := os.MkdirTemp("", "testdata_build")
+	assert.NoError(t, err)
+	defer os.RemoveAll(tmpDir)
+
+	err = copy.Copy(filepath.Join("testdata", "highgoversion"), tmpDir)
+	assert.NoError(t, err)
+
+	// This file causes constant IDE errors, we can't actually have broken go.mod files in the tree
+	os.Rename(filepath.Join(tmpDir, "go.mod.ignore"), filepath.Join(tmpDir, "go.mod"))
+
 	sch := &schema.Schema{
 		Modules: []*schema.Module{
 			schema.Builtins(),
@@ -66,7 +79,7 @@ func TestGoModVersion(t *testing.T) {
 		},
 	}
 	bctx := buildContext{
-		moduleDir: "testdata/highgoversion",
+		moduleDir: tmpDir,
 		buildDir:  ".ftl",
 		sch:       sch,
 	}
diff --git a/internal/buildengine/discover_test.go b/internal/buildengine/discover_test.go
index d8c1377b65..7552a1621b 100644
--- a/internal/buildengine/discover_test.go
+++ b/internal/buildengine/discover_test.go
@@ -2,22 +2,38 @@ package buildengine
 
 import (
 	"context"
+	"os"
+	"path/filepath"
 	"testing"
 
 	"github.com/alecthomas/assert/v2"
 
+	"github.com/otiai10/copy"
+
 	"github.com/TBD54566975/ftl/internal/log"
 	"github.com/TBD54566975/ftl/internal/moduleconfig"
 )
 
 func TestDiscoverModules(t *testing.T) {
 	ctx := log.ContextWithNewDefaultLogger(context.Background())
-	modules, err := DiscoverModules(ctx, []string{"testdata"})
+
+	tmpDir, err := os.MkdirTemp("", "testdata_discover")
+	assert.NoError(t, err)
+	defer os.RemoveAll(tmpDir)
+
+	err = copy.Copy("testdata", tmpDir)
+	assert.NoError(t, err)
+
+	// This file causes constant IDE errors, we can't actually have broken go.mod files in the tree
+	err = os.Rename(filepath.Join(tmpDir, "highgoversion", "go.mod.ignore"), filepath.Join(tmpDir, "highgoversion", "go.mod"))
+	assert.NoError(t, err)
+
+	modules, err := DiscoverModules(ctx, []string{tmpDir})
 	assert.NoError(t, err)
 	expected := []Module{
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:       "testdata/alpha",
+				Dir:       filepath.Join(tmpDir, "alpha"),
 				Language:  "go",
 				Realm:     "home",
 				Module:    "alpha",
@@ -30,7 +46,7 @@ func TestDiscoverModules(t *testing.T) {
 		},
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:       "testdata/another",
+				Dir:       filepath.Join(tmpDir, "another"),
 				Language:  "go",
 				Realm:     "home",
 				Module:    "another",
@@ -43,7 +59,7 @@ func TestDiscoverModules(t *testing.T) {
 		},
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:       "testdata/depcycle1",
+				Dir:       filepath.Join(tmpDir, "depcycle1"),
 				Language:  "go",
 				Realm:     "home",
 				Module:    "depcycle1",
@@ -56,7 +72,7 @@ func TestDiscoverModules(t *testing.T) {
 		},
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:       "testdata/depcycle2",
+				Dir:       filepath.Join(tmpDir, "depcycle2"),
 				Language:  "go",
 				Realm:     "home",
 				Module:    "depcycle2",
@@ -69,7 +85,7 @@ func TestDiscoverModules(t *testing.T) {
 		},
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:      "testdata/echokotlin",
+				Dir:      filepath.Join(tmpDir, "echokotlin"),
 				Language: "kotlin",
 				Realm:    "home",
 				Module:   "echo",
@@ -94,7 +110,7 @@ func TestDiscoverModules(t *testing.T) {
 		},
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:      "testdata/external",
+				Dir:      filepath.Join(tmpDir, "external"),
 				Language: "go",
 				Realm:    "home",
 				Module:   "external",
@@ -114,7 +130,7 @@ func TestDiscoverModules(t *testing.T) {
 		},
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:      "testdata/externalkotlin",
+				Dir:      filepath.Join(tmpDir, "externalkotlin"),
 				Language: "kotlin",
 				Realm:    "home",
 				Module:   "externalkotlin",
@@ -139,7 +155,7 @@ func TestDiscoverModules(t *testing.T) {
 		},
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:       "testdata/highgoversion",
+				Dir:       filepath.Join(tmpDir, "highgoversion"),
 				Language:  "go",
 				Realm:     "home",
 				Module:    "highgoversion",
@@ -152,7 +168,7 @@ func TestDiscoverModules(t *testing.T) {
 		},
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:       "testdata/integer",
+				Dir:       filepath.Join(tmpDir, "integer"),
 				Language:  "go",
 				Realm:     "home",
 				Module:    "integer",
@@ -165,7 +181,7 @@ func TestDiscoverModules(t *testing.T) {
 		},
 		{
 			Config: moduleconfig.ModuleConfig{
-				Dir:       "testdata/other",
+				Dir:       filepath.Join(tmpDir, "other"),
 				Language:  "go",
 				Realm:     "home",
 				Module:    "other",
diff --git a/internal/buildengine/testdata/highgoversion/go.mod b/internal/buildengine/testdata/highgoversion/go.mod.ignore
similarity index 96%
rename from internal/buildengine/testdata/highgoversion/go.mod
rename to internal/buildengine/testdata/highgoversion/go.mod.ignore
index f8f5d9d31b..3a8da338d2 100644
--- a/internal/buildengine/testdata/highgoversion/go.mod
+++ b/internal/buildengine/testdata/highgoversion/go.mod.ignore
@@ -1,5 +1,7 @@
 module ftl/highgoversion
 
+// This file causes intellij errors if it is just called go.mod
+
 go 9000.1.1
 
 require github.com/TBD54566975/ftl v0.177.1