diff --git a/file_log.go b/file_log.go
index 14f0d32b4..99e469d56 100644
--- a/file_log.go
+++ b/file_log.go
@@ -58,7 +58,7 @@ func NewFileLogFactory(settings *Settings) (LogFactory, error) {
 	return logFactory, nil
 }
 
-func (f fileLogFactory) buildFileLog(prefix string, logPath string) (fileLog, error) {
+func newFileLog(prefix string, logPath string) (fileLog, error) {
 	l := fileLog{}
 
 	eventLogName := path.Join(logPath, prefix+".event.current.log")
@@ -68,7 +68,7 @@ func (f fileLogFactory) buildFileLog(prefix string, logPath string) (fileLog, er
 		return l, err
 	}
 
-	fileFlags := os.O_RDWR | os.O_CREATE
+	fileFlags := os.O_RDWR | os.O_CREATE | os.O_APPEND
 	eventFile, err := os.OpenFile(eventLogName, fileFlags, os.ModePerm)
 	if err != nil {
 		return l, err
@@ -86,7 +86,7 @@ func (f fileLogFactory) buildFileLog(prefix string, logPath string) (fileLog, er
 }
 
 func (f fileLogFactory) Create() (Log, error) {
-	return f.buildFileLog("GLOBAL", f.globalLogPath)
+	return newFileLog("GLOBAL", f.globalLogPath)
 }
 
 func (f fileLogFactory) CreateSessionLog(sessionID SessionID) (Log, error) {
@@ -101,5 +101,5 @@ func (f fileLogFactory) CreateSessionLog(sessionID SessionID) (Log, error) {
 		prefixParts = append(prefixParts, sessionID.Qualifier)
 	}
 
-	return f.buildFileLog(strings.Join(prefixParts, "-"), logPath)
+	return newFileLog(strings.Join(prefixParts, "-"), logPath)
 }
diff --git a/file_log_test.go b/file_log_test.go
index b3901ecb5..6f978d06a 100644
--- a/file_log_test.go
+++ b/file_log_test.go
@@ -1,6 +1,10 @@
 package quickfix
 
 import (
+	"bufio"
+	"fmt"
+	"os"
+	"path"
 	"strings"
 	"testing"
 )
@@ -45,3 +49,82 @@ SessionQualifier=BS
 		t.Error("Should have returned factory")
 	}
 }
+
+type fileLogHelper struct {
+	LogPath string
+	Prefix  string
+	Log     Log
+}
+
+func newFileLogHelper(t *testing.T) *fileLogHelper {
+	prefix := "myprefix"
+	logPath := path.Join(os.TempDir(), fmt.Sprintf("TestLogStore-%d", os.Getpid()))
+
+	log, err := newFileLog(prefix, logPath)
+	if err != nil {
+		t.Error("Unexpected error", err)
+	}
+
+	return &fileLogHelper{
+		LogPath: logPath,
+		Prefix:  prefix,
+		Log:     log,
+	}
+}
+
+func TestNewFileLog(t *testing.T) {
+	helper := newFileLogHelper(t)
+
+	tests := []struct {
+		expectedPath string
+	}{
+		{path.Join(helper.LogPath, fmt.Sprintf("%v.messages.current.log", helper.Prefix))},
+		{path.Join(helper.LogPath, fmt.Sprintf("%v.event.current.log", helper.Prefix))},
+	}
+
+	for _, test := range tests {
+		if _, err := os.Stat(test.expectedPath); os.IsNotExist(err) {
+			t.Errorf("%v does not exist", test.expectedPath)
+		}
+	}
+}
+
+func TestFileLog_Append(t *testing.T) {
+	helper := newFileLogHelper(t)
+
+	messageLogFile, err := os.Open(path.Join(helper.LogPath, fmt.Sprintf("%v.messages.current.log", helper.Prefix)))
+	if err != nil {
+		t.Error("Unexpected error", err)
+	}
+	defer messageLogFile.Close()
+
+	eventLogFile, err := os.Open(path.Join(helper.LogPath, fmt.Sprintf("%v.event.current.log", helper.Prefix)))
+	if err != nil {
+		t.Error("Unexpected error", err)
+	}
+	defer eventLogFile.Close()
+
+	messageScanner := bufio.NewScanner(messageLogFile)
+	eventScanner := bufio.NewScanner(eventLogFile)
+
+	helper.Log.OnIncoming("incoming")
+	if !messageScanner.Scan() {
+		t.Error("Unexpected EOF")
+	}
+
+	helper.Log.OnEvent("Event")
+	if !eventScanner.Scan() {
+		t.Error("Unexpected EOF")
+	}
+
+	newHelper := newFileLogHelper(t)
+	newHelper.Log.OnIncoming("incoming")
+	if !messageScanner.Scan() {
+		t.Error("Unexpected EOF")
+	}
+
+	newHelper.Log.OnEvent("Event")
+	if !eventScanner.Scan() {
+		t.Error("Unexpected EOF")
+	}
+}