diff --git a/Makefile.macosx b/Makefile.macosx
index c0fc4e77..9f95ae3d 100644
--- a/Makefile.macosx
+++ b/Makefile.macosx
@@ -68,8 +68,12 @@ endif
 
 # Change as required in support of the available libraries
 
-#CC := $(DARWIN_CC) -m64 $(SYS_LIBS) $(SYS_MIN)
+UNAME_M := $(shell uname -m)
+ifeq (${UNAME_M},x86_64)
+CC := $(DARWIN_CC) -m64 $(SYS_LIBS) $(SYS_MIN)
+else
 CC := $(DARWIN_CC) -m32 $(SYS_LIBS) $(SYS_MIN)
+endif
 CFLAGS := -Os -pthread -Igeotranz $(EXTRA_CFLAGS)
 # $(info $$CC is [${CC}])
 
diff --git a/README.md b/README.md
index 495a9698..171ddc47 100644
--- a/README.md
+++ b/README.md
@@ -80,6 +80,15 @@ This should give you the most recent stable release.  If you want the latest (un
 
 For more details see the **User Guide** in the [doc directory](https://github.com/wb2osz/direwolf/tree/master/doc).  Special considerations for the Raspberry Pi are found in **Raspberry-Pi-APRS.pdf**
 
+## Mac OS X ##
+
+You should have the Xcode developer tools installed. You can then install PortAudio using MacPort, following the instructions in Chapter 6 of the [User Guide](doc/User-Guide.pdf). However, a much simpler method might be to install Homebrew:
+
+1. Install [Homebrew](http://brew.sh/) if you don't have it already
+1. `brew install portaudio`
+
+Finally, follow either of the instructions given above for installing on Linux.
+
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