diff --git a/simgear/debug/debug_types.h b/simgear/debug/debug_types.h
index ed5ee894..2443276b 100644
--- a/simgear/debug/debug_types.h
+++ b/simgear/debug/debug_types.h
@@ -42,6 +42,10 @@ typedef enum {
 
 /**
  * Define the possible logging priorities (and their order).
+ *
+ * Caution - unfortunately, this enum is exposed to Nasal via the logprint()
+ * function as an integer parameter. Therefore, new values should only be
+ * appended, or the priority Nasal reports to compiled code will change.
  */
 typedef enum {
     SG_BULK = 1,       // For frequent messages
@@ -49,8 +53,11 @@ typedef enum {
     SG_INFO,           // Informatory messages
     SG_WARN,           // Possible impending problem
     SG_ALERT,          // Very possible impending problem
-    SG_POPUP           // Severe enough to alert using a pop-up window
+    SG_POPUP,          // Severe enough to alert using a pop-up window
     // SG_EXIT,        // Problem (no core)
     // SG_ABORT        // Abandon ship (core)
+
+    SG_DEV_WARN,       // Warning for developers, translated to other priority
+    SG_DEV_ALERT       // Alert for developers, translated
 } sgDebugPriority;
 
diff --git a/simgear/debug/logstream.cxx b/simgear/debug/logstream.cxx
index e8766c6d..4967422c 100644
--- a/simgear/debug/logstream.cxx
+++ b/simgear/debug/logstream.cxx
@@ -359,6 +359,7 @@ public:
     bool m_stderr_isRedirectedAlready = false;
     bool m_stdout_isRedirectedAlready = false;
 #endif
+    bool m_developerMode = false;
 
     void startLog()
     {
@@ -452,6 +453,7 @@ public:
 
     bool would_log( sgDebugClass c, sgDebugPriority p ) const
     {
+        p = translatePriority(p);
         if (p >= SG_INFO) return true;
         return ((c & m_logClass) != 0 && p >= m_logPriority);
     }
@@ -459,9 +461,23 @@ public:
     void log( sgDebugClass c, sgDebugPriority p,
             const char* fileName, int line, const std::string& msg)
     {
+        p = translatePriority(p);
         LogEntry entry(c, p, fileName, line, msg);
         m_entries.push(entry);
     }
+
+    sgDebugPriority translatePriority(sgDebugPriority in) const
+    {
+        if (in == SG_DEV_WARN) {
+            return m_developerMode ? SG_WARN : SG_DEBUG;
+        }
+
+        if (in == SG_DEV_ALERT) {
+            return m_developerMode ? SG_POPUP : SG_WARN;
+        }
+
+        return in;
+    }
 };
 
 /////////////////////////////////////////////////////////////////////////////
@@ -489,6 +505,12 @@ logstream::setLogLevels( sgDebugClass c, sgDebugPriority p )
     global_privateLogstream->setLogLevels(c, p);
 }
 
+void logstream::setDeveloperMode(bool devMode)
+{
+    global_privateLogstream->m_developerMode = devMode;
+}
+
+
 void
 logstream::addCallback(simgear::LogCallback* cb)
 {
diff --git a/simgear/debug/logstream.hxx b/simgear/debug/logstream.hxx
index 2f7c1ccf..e77ea330 100644
--- a/simgear/debug/logstream.hxx
+++ b/simgear/debug/logstream.hxx
@@ -93,6 +93,13 @@ public:
     
     sgDebugPriority get_log_priority() const;
 
+    /**
+     * set developer mode on/off. In developer mode, SG_DEV_WARN messags
+     * are treated as warnings. In normal (non-developer) mode they are
+     * treated as SG_DEBUG.
+     */
+    void setDeveloperMode(bool devMode);
+
     /**
      * the core logging method
      */