diff --git a/plugin/discovery/find.go b/plugin/discovery/find.go
index 6b9b8b172..c28a60183 100644
--- a/plugin/discovery/find.go
+++ b/plugin/discovery/find.go
@@ -79,7 +79,7 @@ func findPluginPaths(kind string, machineName string, dirs []string) []string {
 					}
 
 					// New-style paths must have a version segment in filename
-					if !strings.Contains(fullName, "-V") {
+					if !strings.Contains(strings.ToLower(fullName), "_v") {
 						continue
 					}
 
@@ -131,11 +131,12 @@ func ResolvePluginPaths(paths []string) PluginMetaSet {
 	found := make(map[nameVersion]struct{})
 
 	for _, path := range paths {
-		baseName := filepath.Base(path)
+		baseName := strings.ToLower(filepath.Base(path))
 		if !strings.HasPrefix(baseName, "terraform-") {
 			// Should never happen with reasonable input
 			continue
 		}
+
 		baseName = baseName[10:]
 		firstDash := strings.Index(baseName, "-")
 		if firstDash == -1 {
@@ -149,7 +150,7 @@ func ResolvePluginPaths(paths []string) PluginMetaSet {
 			continue
 		}
 
-		parts := strings.SplitN(baseName, "-V", 2)
+		parts := strings.SplitN(baseName, "_v", 2)
 		name := parts[0]
 		version := "0.0.0"
 		if len(parts) == 2 {
@@ -158,8 +159,8 @@ func ResolvePluginPaths(paths []string) PluginMetaSet {
 
 		// Auto-installed plugins contain an extra name portion representing
 		// the expected plugin version, which we must trim off.
-		if dashX := strings.Index(version, "-X"); dashX != -1 {
-			version = version[:dashX]
+		if underX := strings.Index(version, "_x"); underX != -1 {
+			version = version[:underX]
 		}
 
 		if _, ok := found[nameVersion{name, version}]; ok {
diff --git a/plugin/discovery/find_test.go b/plugin/discovery/find_test.go
index 887a3ad95..a788882bb 100644
--- a/plugin/discovery/find_test.go
+++ b/plugin/discovery/find_test.go
@@ -19,8 +19,8 @@ func TestFindPluginPaths(t *testing.T) {
 		},
 	)
 	want := []string{
-		filepath.Join("test-fixtures", "current-style-plugins", "mockos_mockarch", "terraform-foo-bar-V0.0.1"),
-		filepath.Join("test-fixtures", "current-style-plugins", "mockos_mockarch", "terraform-foo-bar-V1.0.0"),
+		filepath.Join("test-fixtures", "current-style-plugins", "mockos_mockarch", "terraform-foo-bar_v0.0.1"),
+		filepath.Join("test-fixtures", "current-style-plugins", "mockos_mockarch", "terraform-foo-bar_v1.0.0"),
 		filepath.Join("test-fixtures", "legacy-style-plugins", "terraform-foo-bar"),
 		filepath.Join("test-fixtures", "legacy-style-plugins", "terraform-foo-baz"),
 	}
@@ -50,36 +50,42 @@ func TestFindPluginPaths(t *testing.T) {
 
 func TestResolvePluginPaths(t *testing.T) {
 	got := ResolvePluginPaths([]string{
-		"/example/mockos_mockarch/terraform-foo-bar-V0.0.1",
-		"/example/mockos_mockarch/terraform-foo-baz-V0.0.1",
-		"/example/mockos_mockarch/terraform-foo-baz-V1.0.0",
-		"/example/mockos_mockarch/terraform-foo-baz-V2.0.0-X4",
+		"/example/mockos_mockarch/terraform-foo-bar_v0.0.1",
+		"/example/mockos_mockarch/terraform-foo-baz_v0.0.1",
+		"/example/mockos_mockarch/terraform-foo-baz_v1.0.0",
+		"/example/mockos_mockarch/terraform-foo-baz_v2.0.0_x4",
+		"/example/mockos_mockarch/terraform-foo-upper_V2.0.0_X4",
 		"/example/terraform-foo-bar",
-		"/example/mockos_mockarch/terraform-foo-bar-Vbananas",
-		"/example/mockos_mockarch/terraform-foo-bar-V",
-		"/example2/mockos_mockarch/terraform-foo-bar-V0.0.1",
+		"/example/mockos_mockarch/terraform-foo-bar_vbananas",
+		"/example/mockos_mockarch/terraform-foo-bar_v",
+		"/example2/mockos_mockarch/terraform-foo-bar_v0.0.1",
 	})
 
 	want := []PluginMeta{
 		{
 			Name:    "bar",
 			Version: "0.0.1",
-			Path:    "/example/mockos_mockarch/terraform-foo-bar-V0.0.1",
+			Path:    "/example/mockos_mockarch/terraform-foo-bar_v0.0.1",
 		},
 		{
 			Name:    "baz",
 			Version: "0.0.1",
-			Path:    "/example/mockos_mockarch/terraform-foo-baz-V0.0.1",
+			Path:    "/example/mockos_mockarch/terraform-foo-baz_v0.0.1",
 		},
 		{
 			Name:    "baz",
 			Version: "1.0.0",
-			Path:    "/example/mockos_mockarch/terraform-foo-baz-V1.0.0",
+			Path:    "/example/mockos_mockarch/terraform-foo-baz_v1.0.0",
 		},
 		{
 			Name:    "baz",
 			Version: "2.0.0",
-			Path:    "/example/mockos_mockarch/terraform-foo-baz-V2.0.0-X4",
+			Path:    "/example/mockos_mockarch/terraform-foo-baz_v2.0.0_x4",
+		},
+		{
+			Name:    "upper",
+			Version: "2.0.0",
+			Path:    "/example/mockos_mockarch/terraform-foo-upper_V2.0.0_X4",
 		},
 		{
 			Name:    "bar",
@@ -89,16 +95,18 @@ func TestResolvePluginPaths(t *testing.T) {
 		{
 			Name:    "bar",
 			Version: "bananas",
-			Path:    "/example/mockos_mockarch/terraform-foo-bar-Vbananas",
+			Path:    "/example/mockos_mockarch/terraform-foo-bar_vbananas",
 		},
 		{
 			Name:    "bar",
 			Version: "",
-			Path:    "/example/mockos_mockarch/terraform-foo-bar-V",
+			Path:    "/example/mockos_mockarch/terraform-foo-bar_v",
 		},
 	}
 
-	t.Logf("got %#v", got)
+	for p := range got {
+		t.Logf("got %#v", p)
+	}
 
 	if got, want := got.Count(), len(want); got != want {
 		t.Errorf("got %d items; want %d", got, want)
diff --git a/plugin/discovery/meta_test.go b/plugin/discovery/meta_test.go
index 9249d6f44..3efd3ab34 100644
--- a/plugin/discovery/meta_test.go
+++ b/plugin/discovery/meta_test.go
@@ -7,7 +7,7 @@ import (
 
 func TestMetaSHA256(t *testing.T) {
 	m := PluginMeta{
-		Path: "test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar-V0.0.1",
+		Path: "test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar_v0.0.1",
 	}
 	hash, err := m.SHA256()
 	if err != nil {
diff --git a/plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar-V0.0.1 b/plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar_v0.0.1
similarity index 100%
rename from plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar-V0.0.1
rename to plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar_v0.0.1
diff --git a/plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar-V1.0.0 b/plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar_v1.0.0
similarity index 100%
rename from plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar-V1.0.0
rename to plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-foo-bar_v1.0.0
diff --git a/plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-notfoo-bar-V0.0.1 b/plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-notfoo-bar_v0.0.1
similarity index 100%
rename from plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-notfoo-bar-V0.0.1
rename to plugin/discovery/test-fixtures/current-style-plugins/mockos_mockarch/terraform-notfoo-bar_v0.0.1