diff --git a/radiant/main.cpp b/radiant/main.cpp
index 2fa52214..ede1426f 100644
--- a/radiant/main.cpp
+++ b/radiant/main.cpp
@@ -894,7 +894,11 @@ int main( int argc, char* argv[] ) {
 
 	g_pParentWnd = new MainFrame();
 
-	if ( g_PrefsDlg.m_bLoadLastMap && g_PrefsDlg.m_strLastMap.GetLength() > 0 ) {
+	// If the first parameter is a .map, load that.
+	if( g_argc > 1 && IsMap( g_argv[1] ) ){
+		Map_LoadFile( g_argv[1] );
+	}
+	else if ( g_PrefsDlg.m_bLoadLastMap && g_PrefsDlg.m_strLastMap.GetLength() > 0 ) {
 		Map_LoadFile( g_PrefsDlg.m_strLastMap.GetBuffer() );
 	}
 	else {
diff --git a/radiant/mainframe.cpp b/radiant/mainframe.cpp
index 9368292f..6d24c98b 100644
--- a/radiant/mainframe.cpp
+++ b/radiant/mainframe.cpp
@@ -3619,9 +3619,14 @@ void MainFrame::ShowMenuItemKeyBindings( GtkWidget* window ){
 	}
 }
 
+// Checks whether a given filename ends in .map
+const bool IsMap(const char* filename){
+	return strlen(filename) >= 4 && strcmp(filename + strlen(filename) - 4, ".map") == 0;
+}
+
 void MainFrame::CreateQEChildren(){
-	// load the project file
-	if ( g_argc > 1 ) {
+	// load the project file, if it is a project project file. (Or at least no .map)
+	if ( g_argc > 1 && !IsMap( g_argv[1] ) ) {
 		Sys_Printf( "loading project file from the command line: %s\n", g_argv[1] );
 		if ( !QE_LoadProject( g_argv[1] ) ) {
 			Error( "Unable to load project file %s\n", g_argv[1] );
diff --git a/radiant/mainframe.h b/radiant/mainframe.h
index e72adc4c..3caf5840 100644
--- a/radiant/mainframe.h
+++ b/radiant/mainframe.h
@@ -908,4 +908,7 @@ int gdk_offset_y;
 // some C API to the mainframe functions
 void WINAPI QERApp_Sleep();
 
+// Checks whether a given filename ends in .map
+const bool IsMap(const char* filename);
+
 #endif // _MAINFRAME_H_