diff --git a/doc/cc65.sgml b/doc/cc65.sgml
index 55b84ed5c..383a6dd6a 100644
--- a/doc/cc65.sgml
+++ b/doc/cc65.sgml
@@ -63,6 +63,8 @@ Short options:
   -V                            Print the compiler version number
   -W [-+]warning[,...]          Control warnings ('-' disables, '+' enables)
   -d                            Debug mode
+  -dM                           Output all user macros (needs -E)
+  -dP                           Output all predefined macros (needs -E)
   -g                            Add debug info to object file
   -h                            Help (this text)
   -j                            Default characters are signed
@@ -199,6 +201,28 @@ Here is a description of all the command line options:
   Enables debug mode, for debugging the behavior of cc65.
 
 
+
+  <label id="option-dM">
+  <tag><tt>-dM</tt></tag>
+
+  When used with -E, will output <tt>#define</tt> directives for all the user
+  macros defined during execution of the preprocessor. This does not include
+  macros defined by the compiler.
+
+  Note: Can be combined with <tt/<ref id="option-dP" name="-dP">/ by using
+  <tt/-dMP/.
+
+
+  <label id="option-dP">
+  <tag><tt>-dP</tt></tag>
+
+  When used with -E, will output <tt>#define</tt> directives for all the macros
+  defined by the compiler itself. This does not include any user defined macros.
+
+  Note: Can be combined with <tt/<ref id="option-dM" name="-dM">/ by using
+  <tt/-dMP/.
+
+
   <tag><tt>--debug-tables name</tt></tag>
 
   Writes symbol table information to a file, which includes details on structs, unions
diff --git a/src/cc65/compile.c b/src/cc65/compile.c
index e08a829e6..9083891aa 100644
--- a/src/cc65/compile.c
+++ b/src/cc65/compile.c
@@ -496,6 +496,14 @@ void Compile (const char* FileName)
         while (PreprocessNextLine ())
         { /* Nothing */ }
 
+        /* Output macros if requested by the user */
+        if (DumpPredefMacros) {
+            OutputPredefMacros ();
+        }
+        if (DumpUserMacros) {
+            OutputUserMacros ();
+        }
+
         /* Close the output file */
         CloseOutputFile ();
 
diff --git a/src/cc65/global.c b/src/cc65/global.c
index b2c3ef0a0..64278df77 100644
--- a/src/cc65/global.c
+++ b/src/cc65/global.c
@@ -44,12 +44,14 @@
 
 
 unsigned char AddSource         = 0;    /* Add source lines as comments */
+unsigned char AllowNewComments  = 0;    /* Allow new style comments in C89 mode */
 unsigned char AutoCDecl         = 0;    /* Make functions default to __cdecl__ */
 unsigned char DebugInfo         = 0;    /* Add debug info to the obj */
+unsigned char DumpPredefMacros  = 0;    /* Output predefined macros */
+unsigned char DumpUserMacros    = 0;    /* Output user macros */
 unsigned char PreprocessOnly    = 0;    /* Just preprocess the input */
 unsigned char DebugOptOutput    = 0;    /* Output debug stuff */
 unsigned      RegisterSpace     = 6;    /* Space available for register vars */
-unsigned      AllowNewComments  = 0;    /* Allow new style comments in C89 mode */
 
 /* Stackable options */
 IntStack WritableStrings    = INTSTACK(0);  /* Literal strings are r/w */
diff --git a/src/cc65/global.h b/src/cc65/global.h
index ba7105130..c781f6de4 100644
--- a/src/cc65/global.h
+++ b/src/cc65/global.h
@@ -52,12 +52,14 @@
 
 /* Options */
 extern unsigned char    AddSource;              /* Add source lines as comments */
+extern unsigned char    AllowNewComments;       /* Allow new style comments in C89 mode */
 extern unsigned char    AutoCDecl;              /* Make functions default to __cdecl__ */
 extern unsigned char    DebugInfo;              /* Add debug info to the obj */
+extern unsigned char    DumpPredefMacros;       /* Output predefined macros */
+extern unsigned char    DumpUserMacros;         /* Output user macros */
 extern unsigned char    PreprocessOnly;         /* Just preprocess the input */
 extern unsigned char    DebugOptOutput;         /* Output debug stuff */
 extern unsigned         RegisterSpace;          /* Space available for register vars */
-extern unsigned         AllowNewComments;       /* Allow new style comments in C89 mode */
 
 /* Stackable options */
 extern IntStack         WritableStrings;        /* Literal strings are r/w */
diff --git a/src/cc65/macrotab.c b/src/cc65/macrotab.c
index 3bfae0811..2817403c1 100644
--- a/src/cc65/macrotab.c
+++ b/src/cc65/macrotab.c
@@ -1,4 +1,4 @@
-/*****************************************************************************/
+
 /*                                                                           */
 /*                                macrotab.h                                 */
 /*                                                                           */
@@ -42,6 +42,7 @@
 
 /* cc65 */
 #include "error.h"
+#include "output.h"
 #include "preproc.h"
 #include "macrotab.h"
 
@@ -60,6 +61,70 @@ static Macro* MacroTab[MACRO_TAB_SIZE];
 /* The undefined macros list head */
 static Macro* UndefinedMacrosListHead;
 
+/* Some defines for better readability when calling OutputMacros() */
+#define USER_MACROS     0
+#define PREDEF_MACROS   1
+#define NAME_ONLY       0
+#define FULL_DEFINITION 1
+
+
+
+/*****************************************************************************/
+/*                                  helpers                                  */
+/*****************************************************************************/
+
+
+
+static void OutputMacro (const Macro* M, int Full)
+/* Output one macro. If Full is true, the replacement is also output. */
+{
+    WriteOutput ("#define %s", M->Name);
+    int ParamCount = M->ParamCount;
+    if (M->ParamCount >= 0) {
+        int I;
+        if (M->Variadic) {
+            CHECK (ParamCount > 0);
+            --ParamCount;
+        }
+        WriteOutput ("(");
+        for (I = 0; I < ParamCount; ++I) {
+            const char* Name = CollConstAt (&M->Params, I);
+            WriteOutput ("%s%s", (I == 0)? "" : ",", Name);
+        }
+        if (M->Variadic) {
+            WriteOutput ("%s...", (ParamCount == 0)? "" : ",");
+        }
+        WriteOutput (")");
+    }
+    WriteOutput (" ");
+    if (Full) {
+        WriteOutput ("%.*s",
+                     SB_GetLen (&M->Replacement),
+                     SB_GetConstBuf (&M->Replacement));
+    }
+    WriteOutput ("\n");
+}
+
+
+
+static void OutputMacros (int Predefined, int Full)
+/* Output macros to the output file depending on the flags given. */
+{
+    /* Note: The Full flag is currently not used by any callers but is left in
+    ** place for possible future changes.
+    */
+    unsigned I;
+    for (I = 0; I < MACRO_TAB_SIZE; ++I) {
+        const Macro* M = MacroTab [I];
+        while (M) {
+            if ((Predefined != 0) == (M->Predefined != 0)) {
+                OutputMacro (M, Full);
+            }
+            M = M->Next;
+        }
+    }
+}
+
 
 
 /*****************************************************************************/
@@ -68,7 +133,7 @@ static Macro* UndefinedMacrosListHead;
 
 
 
-Macro* NewMacro (const char* Name)
+Macro* NewMacro (const char* Name, unsigned char Predefined)
 /* Allocate a macro structure with the given name. The structure is not
 ** inserted into the macro table.
 */
@@ -84,6 +149,7 @@ Macro* NewMacro (const char* Name)
     M->ParamCount   = -1;        /* Flag: Not a function-like macro */
     InitCollection (&M->Params);
     SB_Init (&M->Replacement);
+    M->Predefined   = Predefined;
     M->Variadic     = 0;
     memcpy (M->Name, Name, Len+1);
 
@@ -116,7 +182,7 @@ Macro* CloneMacro (const Macro* M)
 ** Use FreeMacro for that.
 */
 {
-    Macro* New = NewMacro (M->Name);
+    Macro* New = NewMacro (M->Name, M->Predefined);
     unsigned I;
 
     for (I = 0; I < CollCount (&M->Params); ++I) {
@@ -134,7 +200,7 @@ Macro* CloneMacro (const Macro* M)
 
 
 void DefineNumericMacro (const char* Name, long Val)
-/* Define a macro for a numeric constant */
+/* Define a predefined macro for a numeric constant */
 {
     char Buf[64];
 
@@ -148,10 +214,10 @@ void DefineNumericMacro (const char* Name, long Val)
 
 
 void DefineTextMacro (const char* Name, const char* Val)
-/* Define a macro for a textual constant */
+/* Define a predefined macro for a textual constant */
 {
     /* Create a new macro */
-    Macro* M = NewMacro (Name);
+    Macro* M = NewMacro (Name, 1);
 
     /* Set the value as replacement text */
     SB_CopyStr (&M->Replacement, Val);
@@ -350,3 +416,19 @@ void PrintMacroStats (FILE* F)
         }
     }
 }
+
+
+
+void OutputPredefMacros (void)
+/* Output all predefined macros to the output file */
+{
+    OutputMacros (PREDEF_MACROS, FULL_DEFINITION);
+}
+
+
+
+void OutputUserMacros (void)
+/* Output all user defined macros to the output file */
+{
+    OutputMacros (USER_MACROS, FULL_DEFINITION);
+}
diff --git a/src/cc65/macrotab.h b/src/cc65/macrotab.h
index 52b812b2f..00fb1d55a 100644
--- a/src/cc65/macrotab.h
+++ b/src/cc65/macrotab.h
@@ -58,6 +58,7 @@ struct Macro {
     int           ParamCount;   /* Number of parameters, -1 = no parens */
     Collection    Params;       /* Parameter list (char*) */
     StrBuf        Replacement;  /* Replacement text */
+    unsigned char Predefined;   /* True if this is a predefined macro */
     unsigned char Variadic;     /* C99 variadic macro */
     char          Name[1];      /* Name, dynamically allocated */
 };
@@ -70,7 +71,7 @@ struct Macro {
 
 
 
-Macro* NewMacro (const char* Name);
+Macro* NewMacro (const char* Name, unsigned char Predefined);
 /* Allocate a macro structure with the given name. The structure is not
 ** inserted into the macro table.
 */
@@ -87,10 +88,10 @@ Macro* CloneMacro (const Macro* M);
 */
 
 void DefineNumericMacro (const char* Name, long Val);
-/* Define a macro for a numeric constant */
+/* Define a predefined macro for a numeric constant */
 
 void DefineTextMacro (const char* Name, const char* Val);
-/* Define a macro for a textual constant */
+/* Define a predefined macro for a textual constant */
 
 void InsertMacro (Macro* M);
 /* Insert the given macro into the macro table. */
@@ -132,6 +133,12 @@ int MacroCmp (const Macro* M1, const Macro* M2);
 void PrintMacroStats (FILE* F);
 /* Print macro statistics to the given text file. */
 
+void OutputPredefMacros (void);
+/* Output all predefined macros to the output file */
+
+void OutputUserMacros (void);
+/* Output all user defined macros to the output file */
+
 
 
 /* End of macrotab.h */
diff --git a/src/cc65/main.c b/src/cc65/main.c
index 53b106abd..5b951dc56 100644
--- a/src/cc65/main.c
+++ b/src/cc65/main.c
@@ -93,6 +93,8 @@ static void Usage (void)
             "  -V\t\t\t\tPrint the compiler version number\n"
             "  -W [-+]warning[,...]\t\tControl warnings ('-' disables, '+' enables)\n"
             "  -d\t\t\t\tDebug mode\n"
+            "  -dM\t\t\t\tOutput all user macros (needs -E)\n"
+            "  -dP\t\t\t\tOutput all predefined macros (needs -E)\n"
             "  -g\t\t\t\tAdd debug info to object file\n"
             "  -h\t\t\t\tHelp (this text)\n"
             "  -j\t\t\t\tDefault characters are signed\n"
@@ -1026,7 +1028,25 @@ int main (int argc, char* argv[])
                     break;
 
                 case 'd':
-                    OptDebug (Arg, 0);
+                    P = Arg + 2;
+                    if (*P == '\0') {
+                        OptDebug (Arg, 0);
+                    } else {
+                        while (*P) {
+                            switch (*P) {
+                                case 'M':
+                                    DumpUserMacros = 1;
+                                    break;
+                                case 'P':
+                                    DumpPredefMacros = 1;
+                                    break;
+                                default:
+                                    UnknownOption (Arg);
+                                    break;
+                            }
+                            ++P;
+                        }
+                    }
                     break;
 
                 case 'h':
@@ -1138,6 +1158,11 @@ int main (int argc, char* argv[])
         AbEnd ("No input files");
     }
 
+    /* The options to output macros can only be used with -E */
+    if ((DumpPredefMacros || DumpUserMacros) && !PreprocessOnly) {
+        AbEnd ("Preprocessor macro output can only be used together with -E");
+    }
+
     /* Add the default include search paths. */
     FinishIncludePaths ();
 
diff --git a/src/cc65/preproc.c b/src/cc65/preproc.c
index 96fa565f2..65db5ea57 100644
--- a/src/cc65/preproc.c
+++ b/src/cc65/preproc.c
@@ -2575,7 +2575,7 @@ static void DoDefine (void)
     CheckForBadIdent (Ident, Std, 0);
 
     /* Create a new macro definition */
-    M = NewMacro (Ident);
+    M = NewMacro (Ident, 0);
 
     /* Check if this is a function-like macro */
     if (CurC == '(') {