diff --git a/direct/src/plugin_npapi/startup.cxx b/direct/src/plugin_npapi/startup.cxx
index 6994d85998..bb4eeec3a2 100644
--- a/direct/src/plugin_npapi/startup.cxx
+++ b/direct/src/plugin_npapi/startup.cxx
@@ -116,9 +116,9 @@ open_logfile() {
 //               get the mimetypes and extensions this plugin is
 //               supposed to handle.
 ////////////////////////////////////////////////////////////////////
-char*
+const char*
 NP_GetMIMEDescription(void) {
-  return (char*) "application/x-panda3d:p3d:Panda3D applet;";
+  return (const char*) "application/x-panda3d:p3d:Panda3D applet;";
 }
 
 ////////////////////////////////////////////////////////////////////
diff --git a/direct/src/plugin_npapi/startup.h b/direct/src/plugin_npapi/startup.h
index 2980a3d18e..959f139281 100644
--- a/direct/src/plugin_npapi/startup.h
+++ b/direct/src/plugin_npapi/startup.h
@@ -29,7 +29,7 @@ extern "C" {
                                NPPluginFuncs *pluginFuncs);
 #endif
 
-  char* NP_GetMIMEDescription(void);
+  const char* NP_GetMIMEDescription(void);
   NPError NP_GetValue(void*, NPPVariable variable, void* value);
   NPError OSCALL NP_GetEntryPoints(NPPluginFuncs *pluginFuncs);
   NPError OSCALL NP_Shutdown(void);