diff --git a/config.guess b/config.guess
index 69ed3e5..92fbce9 100755
--- a/config.guess
+++ b/config.guess
@@ -1311,6 +1311,14 @@ EOF
 			i386) UNAME_PROCESSOR=x86_64 ;;
 			powerpc) UNAME_PROCESSOR=powerpc64 ;;
 		    esac
+		else
+		    # On 10.4-10.6 one might compile for PowerPC via 'gcc -arch ppc'
+		    if (echo '#ifdef __POWERPC__'; echo IS_PPC; echo '#endif') | \
+			(CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
+			grep IS_PPC >/dev/null
+		    then
+			UNAME_PROCESSOR=powerpc
+		    fi
 		fi
 	    fi
 	elif test "$UNAME_PROCESSOR" = i386 ; then