diff --git a/cmd/piper.go b/cmd/piper.go
index 1817048c1..33532bbcd 100644
--- a/cmd/piper.go
+++ b/cmd/piper.go
@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path/filepath"
+	"strings"
 
 	"github.com/SAP/jenkins-library/pkg/config"
 	"github.com/SAP/jenkins-library/pkg/log"
@@ -100,20 +102,18 @@ func PrepareConfig(cmd *cobra.Command, metadata *config.StepData, stepName strin
 		var err error
 		//accept that config file and defaults cannot be loaded since both are not mandatory here
 		{
-			exists, e := piperutils.FileExists(GeneralConfig.CustomConfig)
-
-			if e != nil {
-				return e
-			}
+			projectConfigFile := getProjectConfigFile(GeneralConfig.CustomConfig)
 
+			exists, err := piperutils.FileExists(projectConfigFile)
 			if exists {
-				if customConfig, err = openFile(GeneralConfig.CustomConfig); err != nil {
-					errors.Wrapf(err, "Cannot read '%s'", GeneralConfig.CustomConfig)
+				if customConfig, err = openFile(projectConfigFile); err != nil {
+					errors.Wrapf(err, "Cannot read '%s'", projectConfigFile)
 				}
 			} else {
-				log.Entry().Infof("Project config file '%s' does not exist. No project configuration available.", GeneralConfig.CustomConfig)
+				log.Entry().Infof("Project config file '%s' does not exist. No project configuration available.", projectConfigFile)
 				customConfig = nil
 			}
+
 		}
 		var defaultConfig []io.ReadCloser
 		for _, f := range GeneralConfig.DefaultConfig {
@@ -145,3 +145,22 @@ func PrepareConfig(cmd *cobra.Command, metadata *config.StepData, stepName strin
 
 	return nil
 }
+
+func getProjectConfigFile(name string) string {
+
+	var altName string
+	if ext := filepath.Ext(name); ext == ".yml" {
+		altName = fmt.Sprintf("%v.yaml", strings.TrimSuffix(name, ext))
+	} else if ext == "yaml" {
+		altName = fmt.Sprintf("%v.yml", strings.TrimSuffix(name, ext))
+	}
+
+	fileExists, _ := piperutils.FileExists(name)
+	altExists, _ := piperutils.FileExists(altName)
+
+	// configured filename will always take precedence, even if not existing
+	if !fileExists && altExists {
+		return altName
+	}
+	return name
+}
diff --git a/cmd/piper_test.go b/cmd/piper_test.go
index 9d612d59b..ab2f61053 100644
--- a/cmd/piper_test.go
+++ b/cmd/piper_test.go
@@ -1,8 +1,11 @@
 package cmd
 
 import (
+	"fmt"
 	"io"
 	"io/ioutil"
+	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -195,3 +198,38 @@ func TestPrepareConfig(t *testing.T) {
 		})
 	})
 }
+
+func TestGetProjectConfigFile(t *testing.T) {
+
+	tt := []struct {
+		filename       string
+		filesAvailable []string
+		expected       string
+	}{
+		{filename: ".pipeline/config.yml", filesAvailable: []string{}, expected: ".pipeline/config.yml"},
+		{filename: ".pipeline/config.yml", filesAvailable: []string{".pipeline/config.yml"}, expected: ".pipeline/config.yml"},
+		{filename: ".pipeline/config.yml", filesAvailable: []string{".pipeline/config.yaml"}, expected: ".pipeline/config.yaml"},
+		{filename: ".pipeline/config.yaml", filesAvailable: []string{".pipeline/config.yml", ".pipeline/config.yaml"}, expected: ".pipeline/config.yaml"},
+		{filename: ".pipeline/config.yml", filesAvailable: []string{".pipeline/config.yml", ".pipeline/config.yaml"}, expected: ".pipeline/config.yml"},
+	}
+
+	for run, test := range tt {
+		t.Run(fmt.Sprintf("Run %v", run), func(t *testing.T) {
+			dir, err := ioutil.TempDir("", "")
+			defer os.RemoveAll(dir) // clean up
+			assert.NoError(t, err)
+
+			if len(test.filesAvailable) > 0 {
+				configFolder := filepath.Join(dir, filepath.Dir(test.filesAvailable[0]))
+				err = os.MkdirAll(configFolder, 0700)
+				assert.NoError(t, err)
+			}
+
+			for _, file := range test.filesAvailable {
+				ioutil.WriteFile(filepath.Join(dir, file), []byte("general:"), 0700)
+			}
+
+			assert.Equal(t, filepath.Join(dir, test.expected), getProjectConfigFile(filepath.Join(dir, test.filename)))
+		})
+	}
+}