diff --git a/nsprpub/pr/include/prlog.h b/nsprpub/pr/include/prlog.h
index 50d4aba7e8d..d8e82d51166 100644
--- a/nsprpub/pr/include/prlog.h
+++ b/nsprpub/pr/include/prlog.h
@@ -170,6 +170,12 @@ PR_EXTERN(void) PR_LogPrint(const char *fmt, ...);
 */
 PR_EXTERN(void) PR_LogFlush(void);
 
+/* Need external access to this on Mac so we can first set up our faux environment vars */
+#ifdef XP_MAC
+PR_EXTERN(void) PR_Init_Log(void);
+#endif
+
+
 /*
 ** Windoze 16 can't support a large static string space for all of the
 ** various debugging strings so logging is not enabled for it.
diff --git a/nsprpub/pr/src/io/prlog.c b/nsprpub/pr/src/io/prlog.c
index 6d7e4e166b0..24dbfddee45 100644
--- a/nsprpub/pr/src/io/prlog.c
+++ b/nsprpub/pr/src/io/prlog.c
@@ -481,3 +481,12 @@ PR_IMPLEMENT(void) PR_Assert(const char *s, const char *file, PRIntn ln)
 #endif
 #endif /* PR_LOGGING */
 }
+
+#ifdef XP_MAC
+PR_IMPLEMENT(void) PR_Init_Log(void)
+{
+#ifdef PR_LOGGING
+	_PR_InitLog();
+#endif
+}
+#endif
diff --git a/xpfe/appshell/src/nsCommandLineServiceMac.cpp b/xpfe/appshell/src/nsCommandLineServiceMac.cpp
index 8ad74468a86..e3e39d87c11 100644
--- a/xpfe/appshell/src/nsCommandLineServiceMac.cpp
+++ b/xpfe/appshell/src/nsCommandLineServiceMac.cpp
@@ -45,6 +45,7 @@ static NS_DEFINE_CID(kIOServiceCID, NS_IOSERVICE_CID);
 #include "prmem.h"
 #include "plstr.h"
 #include "prenv.h"
+#include "prlog.h"
 
 // Universal
 #include <AppleEvents.h>
@@ -512,6 +513,7 @@ OSErr nsAppleEventHandler::HandleOpen1Doc(const FSSpec& inFileSpec, OSType inFil
 			if (s.is_open())
 			{
 				Boolean foundArgs = false;
+				Boolean foundEnv = false;
 				char chars[1024];
 				const char* kCommandLinePrefix = "ARGS:";
 				const char* kEnvVarLinePrefix = "ENV:";
@@ -527,7 +529,7 @@ OSErr nsAppleEventHandler::HandleOpen1Doc(const FSSpec& inFileSpec, OSType inFil
 					else if (PL_strstr(chars, kEnvVarLinePrefix) == chars)
 					{
 						(void)AddToEnvironmentVars(chars + PL_strlen(kEnvVarLinePrefix));
-						foundArgs = true;
+						foundEnv = true;
 					}
 					
 					// Clear the buffer and get the next line from the command line file
@@ -535,9 +537,14 @@ OSErr nsAppleEventHandler::HandleOpen1Doc(const FSSpec& inFileSpec, OSType inFil
 					s.readline(chars, sizeof(chars));
 				} while (PL_strlen(chars));
 				
+				// If we found any environment vars we need to re-init NSPR's logging
+				// so that it knows what the new vars are
+				if (foundEnv)
+					PR_Init_Log();
+
 				// If we found a command line or environment vars we want to return now
 				// raather than trying to open the file as a URL
-				if (foundArgs)
+				if (foundArgs || foundEnv)
 					return noErr;
 			}
 		}
diff --git a/xpfe/components/startup/src/nsCommandLineServiceMac.cpp b/xpfe/components/startup/src/nsCommandLineServiceMac.cpp
index 8ad74468a86..e3e39d87c11 100644
--- a/xpfe/components/startup/src/nsCommandLineServiceMac.cpp
+++ b/xpfe/components/startup/src/nsCommandLineServiceMac.cpp
@@ -45,6 +45,7 @@ static NS_DEFINE_CID(kIOServiceCID, NS_IOSERVICE_CID);
 #include "prmem.h"
 #include "plstr.h"
 #include "prenv.h"
+#include "prlog.h"
 
 // Universal
 #include <AppleEvents.h>
@@ -512,6 +513,7 @@ OSErr nsAppleEventHandler::HandleOpen1Doc(const FSSpec& inFileSpec, OSType inFil
 			if (s.is_open())
 			{
 				Boolean foundArgs = false;
+				Boolean foundEnv = false;
 				char chars[1024];
 				const char* kCommandLinePrefix = "ARGS:";
 				const char* kEnvVarLinePrefix = "ENV:";
@@ -527,7 +529,7 @@ OSErr nsAppleEventHandler::HandleOpen1Doc(const FSSpec& inFileSpec, OSType inFil
 					else if (PL_strstr(chars, kEnvVarLinePrefix) == chars)
 					{
 						(void)AddToEnvironmentVars(chars + PL_strlen(kEnvVarLinePrefix));
-						foundArgs = true;
+						foundEnv = true;
 					}
 					
 					// Clear the buffer and get the next line from the command line file
@@ -535,9 +537,14 @@ OSErr nsAppleEventHandler::HandleOpen1Doc(const FSSpec& inFileSpec, OSType inFil
 					s.readline(chars, sizeof(chars));
 				} while (PL_strlen(chars));
 				
+				// If we found any environment vars we need to re-init NSPR's logging
+				// so that it knows what the new vars are
+				if (foundEnv)
+					PR_Init_Log();
+
 				// If we found a command line or environment vars we want to return now
 				// raather than trying to open the file as a URL
-				if (foundArgs)
+				if (foundArgs || foundEnv)
 					return noErr;
 			}
 		}