diff --git a/include/cc65.h b/include/cc65.h
index 7e9c2cae2..99a8665c8 100644
--- a/include/cc65.h
+++ b/include/cc65.h
@@ -36,6 +36,12 @@
 #ifndef _CC65_H
 #define _CC65_H
 
+typedef enum {
+    CC65_EXIT_SUCCESS,
+    CC65_EXIT_FAILURE,
+    CC65_EXIT_AFAILED,
+    CC65_EXIT_ABORT
+} cc65_exit_codes_t;
 
 
 /*****************************************************************************/
diff --git a/libsrc/common/_afailed.c b/libsrc/common/_afailed.c
index ed93fc12d..654025e1a 100644
--- a/libsrc/common/_afailed.c
+++ b/libsrc/common/_afailed.c
@@ -17,5 +17,5 @@ void __fastcall__ _afailed (char* file, unsigned line)
 {
     raise (SIGABRT);
     fprintf (stderr, "ASSERTION FAILED IN %s(%u)\n", file, line);
-    exit (2);
+    exit (CC65_EXIT_AFAILED);
 }
diff --git a/libsrc/common/abort.c b/libsrc/common/abort.c
index 43ad676a7..e59adb7d3 100644
--- a/libsrc/common/abort.c
+++ b/libsrc/common/abort.c
@@ -16,7 +16,7 @@ void abort (void)
 {
     raise (SIGABRT);
     fputs ("ABNORMAL PROGRAM TERMINATION\n", stderr);
-    exit (3);
+    exit (CC65_EXIT_ABORT);
 }
 
 
diff --git a/libsrc/dbg/dbg.c b/libsrc/dbg/dbg.c
index 60b452799..1b08d7750 100644
--- a/libsrc/dbg/dbg.c
+++ b/libsrc/dbg/dbg.c
@@ -1580,7 +1580,7 @@ void DbgEntry (void)
             case 'q':
                 /* Quit program */
                 clrscr ();
-                exit (1);
+                exit (CC65_EXIT_FAILURE);
 
         }
     }
diff --git a/libsrc/geos-apple/targetutil/convert.c b/libsrc/geos-apple/targetutil/convert.c
index ea9273fc3..a4d07ac0a 100644
--- a/libsrc/geos-apple/targetutil/convert.c
+++ b/libsrc/geos-apple/targetutil/convert.c
@@ -5,6 +5,7 @@
 #include <dirent.h>
 #include <device.h>
 #include <dio.h>
+#include <cc65.h>
 
 unsigned char info_signature[3] = {3, 21, 63 | 0x80};
 
@@ -69,7 +70,7 @@ static void err_exit(char *operation, unsigned char oserr)
                 operation);
     }
     getchar();
-    exit(EXIT_FAILURE);
+    exit(CC65_EXIT_FAILURE);
 }
 
 
@@ -342,5 +343,5 @@ int main(int argc, char* argv[])
     printf("Convert to '%.*s' successful", dir_entry->storage_length.name_length,
                                            dir_entry->file_name);
     getchar();
-    return EXIT_SUCCESS;
+    return CC65_EXIT_SUCCESS;
 }
diff --git a/libsrc/geos-common/common/_afailed.c b/libsrc/geos-common/common/_afailed.c
index 2448534c0..ec21a6b4e 100644
--- a/libsrc/geos-common/common/_afailed.c
+++ b/libsrc/geos-common/common/_afailed.c
@@ -28,5 +28,5 @@ void _afailed (char* file, unsigned line)
 
     DlgBoxOk(CBOLDON "ASSERTION FAILED", "PROGRAM TERMINATED" CPLAINTEXT);
 
-    exit (2);
+    exit (CC65_EXIT_AFAILED);
 }
diff --git a/libsrc/geos-common/common/abort.c b/libsrc/geos-common/common/abort.c
index b7cb35eb9..665b70863 100644
--- a/libsrc/geos-common/common/abort.c
+++ b/libsrc/geos-common/common/abort.c
@@ -6,10 +6,11 @@
 
 #include <stdlib.h>
 #include <geos.h>
+#include <cc65.h>
 
 void abort (void)
 {
     ExitTurbo();
     DlgBoxOk(CBOLDON "ABNORMAL PROGRAM", "TERMINATION." CPLAINTEXT);
-    exit(3);
+    exit(CC65_EXIT_ABORT);
 }