diff --git a/src/clock.c b/src/clock.c
index 52af58b..c4b5501 100644
--- a/src/clock.c
+++ b/src/clock.c
@@ -183,7 +183,7 @@ clk_calculate_bram_checksum(void) {
 		}
 		checksum &= 0xFFFF;
 		checksum += ((checksum ^ 0xAAAA) << 16);
-#ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 		g_bram_ptr[252] = (checksum & 0xFF);
 		g_bram_ptr[253] = (checksum >> 8);
 		g_bram_ptr[254] = (checksum >> 16);
diff --git a/src/iwm.c b/src/iwm.c
index d311057..b4c9201 100644
--- a/src/iwm.c
+++ b/src/iwm.c
@@ -1898,7 +1898,7 @@ iwm_nibblize_track_525(Disk *dsk, Trk *trk, byte *track_buf, int qtr_track)
 
 
 	word_ptr = (word32 *)&(trk->nib_area[0]);
-#ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 	val = 0xff08ff08;
 #else
 	val = 0x08ff08ff;
@@ -2003,7 +2003,7 @@ iwm_nibblize_track_35(Disk *dsk, Trk *trk, byte *track_buf, int qtr_track)
 	int	i;
 
 	word_ptr = (word32 *)&(trk->nib_area[0]);
-#ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__)
 	val = 0xff08ff08;
 #else
 	val = 0x08ff08ff;
diff --git a/src/smartport.c b/src/smartport.c
index 4bf3bb2..35591f3 100644
--- a/src/smartport.c
+++ b/src/smartport.c
@@ -642,7 +642,7 @@ do_write_c7(int unit_num, word32 buf, int blk)
 		val1 = get_memory16_c(buf + i, 0);
 		val2 = get_memory16_c(buf + i + 2, 0);
 		/* reorder the little-endian bytes to be big-endian */
-#ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 		val = (val2 << 16) + val1;
 #else
 		val = (val1 << 24) + ((val1 << 8) & 0xff0000) +
diff --git a/src/sound.c b/src/sound.c
index 78bf09c..59c4944 100644
--- a/src/sound.c
+++ b/src/sound.c
@@ -1,6 +1,6 @@
 /*
  GSport - an Apple //gs Emulator
- Copyright (C) 2010 by GSport contributors
+ Copyright (C) 2010 - 2012 by GSport contributors
  
  Based on the KEGS emulator written by and Copyright (C) 2003 Kent Dickey
 
@@ -1058,7 +1058,7 @@ sound_play(double dsamps)
 #if defined(__linux__) || defined(OSS)
 				/* Linux seems to expect little-endian */
 				/*  samples always, even on PowerPC */
-# ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 				sndptr[pos] = (val << 16) + (val0 & 0xffff);
 # else
 				sndptr[pos] = ((val & 0xff) << 24) +
@@ -1067,7 +1067,7 @@ sound_play(double dsamps)
 						((val0 >> 8) & 0xff);
 # endif
 #else
-# ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 				sndptr[pos] = (val << 16) + (val0 & 0xffff);
 # else
 				sndptr[pos] = (val0 << 16) + (val & 0xffff);
diff --git a/src/sound_driver.c b/src/sound_driver.c
index 5c8e6e2..cd55dd0 100644
--- a/src/sound_driver.c
+++ b/src/sound_driver.c
@@ -1,6 +1,6 @@
 /*
  GSport - an Apple //gs Emulator
- Copyright (C) 2010 by GSport contributors
+ Copyright (C) 2010 - 2012 by GSport contributors
  
  Based on the KEGS emulator written by and Copyright (C) 2003 Kent Dickey
 
@@ -398,7 +398,7 @@ child_sound_init_linux()
 		exit(1);
 	}
 
-#ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 	fmt = AFMT_S16_LE;
 #else
 	fmt = AFMT_S16_BE;
diff --git a/src/video.c b/src/video.c
index dc818d2..965c248 100644
--- a/src/video.c
+++ b/src/video.c
@@ -1,6 +1,6 @@
 /*
  GSport - an Apple //gs Emulator
- Copyright (C) 2010 by GSport contributors
+ Copyright (C) 2010 - 2012 by GSport contributors
  
  Based on the KEGS emulator written by and Copyright (C) 2003 Kent Dickey
 
@@ -516,7 +516,7 @@ video_init()
 		val1 = g_dhires_colors_16[col[1] & 0xf];
 		val2 = g_dhires_colors_16[col[2] & 0xf];
 		val3 = g_dhires_colors_16[col[3] & 0xf];
-#ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 		val = (val3 << 24) + (val2 << 16) + (val1 << 8) + val0;
 #else
 		val = (val0 << 24) + (val1 << 16) + (val2 << 8) + val3;
@@ -1622,7 +1622,7 @@ redraw_changed_gr(int start_offset, int start_line, int num_lines, int reparse,
 						(val0 << 8) + val0;
 				val1_wd = (val1 << 24) + (val1 << 16) +
 						(val1 << 8) + val1;
-#ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 				val01_wd = (val1_wd << 16) + (val0_wd & 0xffff);
 #else
 				val01_wd = (val0_wd << 16) + (val1_wd & 0xffff);
@@ -1762,7 +1762,7 @@ redraw_changed_dbl_gr(int start_offset, int start_line, int num_lines,
 						(val2 << 8) + val2;
 				val3_wd = (val3 << 24) + (val3 << 16) +
 						(val3 << 8) + val3;
-#ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 				val01_wd = (val1_wd << 24) + (val0_wd&0xffffff);
 				val12_wd = (val2_wd << 16) + (val1_wd & 0xffff);
 				val23_wd = (val3_wd << 8) + (val2_wd & 0xff);
diff --git a/src/xdriver.c b/src/xdriver.c
index 7de5e92..6a71182 100644
--- a/src/xdriver.c
+++ b/src/xdriver.c
@@ -895,7 +895,7 @@ get_ximage(Kimage *kimage_ptr)
 	xim = XCreateImage(g_display, g_vis, depth, ZPixmap, 0,
 		(char *)ptr, width, height, 8, 0);
 
-#ifdef GSPORT_LITTLE_ENDIAN
+#if defined(GSPORT_LITTLE_ENDIAN) || defined (__LITTLE_ENDIAN__) // OSX needs to calculate endianness mid-compilation, can't be passed on compile command
 	xim->byte_order = LSBFirst;
 #else
 	xim->byte_order = MSBFirst;