diff --git a/make-macosx-ub.sh b/make-macosx-ub.sh
index fd472f9b..495984b4 100755
--- a/make-macosx-ub.sh
+++ b/make-macosx-ub.sh
@@ -73,13 +73,19 @@ echo "Building PPC Client/Dedicated Server against \"$PPC_SDK\""
 echo
 
 # For parallel make on multicore boxes...
-NCPU=`sysctl -n hw.ncpu`
+SYSCTL_PATH=`command -v sysctl 2> /dev/null`
+if [ -n "$SYSCTL_PATH" ]; then
+	NCPU=`sysctl -n hw.ncpu`
+else
+	# osxcross on linux
+	NCPU=`nproc`
+fi
 
 # x86_64 client and server
 #if [ -d build/release-release-x86_64 ]; then
 #	rm -r build/release-darwin-x86_64
 #fi
-(ARCH=x86_64 CC=gcc-4.0 CFLAGS=$X86_64_CFLAGS MACOSX_VERSION_MIN=$X86_64_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
+(PLATFORM=darwin ARCH=x86_64 CC=gcc-4.0 CFLAGS=$X86_64_CFLAGS MACOSX_VERSION_MIN=$X86_64_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
 
 echo;echo
 
@@ -87,7 +93,7 @@ echo;echo
 #if [ -d build/release-darwin-x86 ]; then
 #	rm -r build/release-darwin-x86
 #fi
-(ARCH=x86 CC=gcc-4.0 CFLAGS=$X86_CFLAGS MACOSX_VERSION_MIN=$X86_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
+(PLATFORM=darwin ARCH=x86 CC=gcc-4.0 CFLAGS=$X86_CFLAGS MACOSX_VERSION_MIN=$X86_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
 
 echo;echo
 
@@ -95,7 +101,7 @@ echo;echo
 #if [ -d build/release-darwin-ppc ]; then
 #	rm -r build/release-darwin-ppc
 #fi
-(ARCH=ppc CC=gcc-4.0 CFLAGS=$PPC_CFLAGS MACOSX_VERSION_MIN=$PPC_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
+(PLATFORM=darwin ARCH=ppc CC=gcc-4.0 CFLAGS=$PPC_CFLAGS MACOSX_VERSION_MIN=$PPC_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
 
 echo
 
diff --git a/make-macosx-ub2.sh b/make-macosx-ub2.sh
index 62ab6cbb..a364b853 100755
--- a/make-macosx-ub2.sh
+++ b/make-macosx-ub2.sh
@@ -28,13 +28,19 @@ if [ "$1" == "" ]; then
 fi
 
 # For parallel make on multicore boxes...
-NCPU=`sysctl -n hw.ncpu`
+SYSCTL_PATH=`command -v sysctl 2> /dev/null`
+if [ -n "$SYSCTL_PATH" ]; then
+	NCPU=`sysctl -n hw.ncpu`
+else
+	# osxcross on linux
+	NCPU=`nproc`
+fi
 
 # x86_64 client and server
 #if [ -d build/release-release-x86_64 ]; then
 #	rm -r build/release-darwin-x86_64
 #fi
-(ARCH=x86_64 CFLAGS=$X86_64_CFLAGS MACOSX_VERSION_MIN=$X86_64_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
+(PLATFORM=darwin ARCH=x86_64 CFLAGS=$X86_64_CFLAGS MACOSX_VERSION_MIN=$X86_64_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
 
 echo;echo
 
@@ -42,7 +48,7 @@ echo;echo
 #if [ -d build/release-release-arm64 ]; then
 #	rm -r build/release-darwin-arm64
 #fi
-(ARCH=arm64 CFLAGS=$ARM64_CFLAGS MACOSX_VERSION_MIN=$ARM64_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
+(PLATFORM=darwin ARCH=arm64 CFLAGS=$ARM64_CFLAGS MACOSX_VERSION_MIN=$ARM64_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
 
 echo
 
@@ -150,4 +156,4 @@ if [ "$1" == "notarize" ]; then
 	ditto -c -k --sequesterRsrc --keepParent ${RELEASE_BUILD} ${POST_NOTARIZED_ZIP}
 
 	echo "done. ${POST_NOTARIZED_ZIP} contains notarized ${RELEASE_BUILD} build."
-fi
\ No newline at end of file
+fi
diff --git a/make-macosx.sh b/make-macosx.sh
index ed5dd40f..e7cdfd48 100755
--- a/make-macosx.sh
+++ b/make-macosx.sh
@@ -106,14 +106,19 @@ if [ ! -d $DESTDIR ]; then
 fi
 
 # For parallel make on multicore boxes...
-NCPU=`sysctl -n hw.ncpu`
-
+SYSCTL_PATH=`command -v sysctl 2> /dev/null`
+if [ -n "$SYSCTL_PATH" ]; then
+	NCPU=`sysctl -n hw.ncpu`
+else
+	# osxcross on linux
+	NCPU=`nproc`
+fi
 
 # intel client and server
 #if [ -d build/release-darwin-${BUILDARCH} ]; then
 #	rm -r build/release-darwin-${BUILDARCH}
 #fi
-(ARCH=${BUILDARCH} CFLAGS=$ARCH_CFLAGS MACOSX_VERSION_MIN=$ARCH_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
+(PLATFORM=darwin ARCH=${BUILDARCH} CFLAGS=$ARCH_CFLAGS MACOSX_VERSION_MIN=$ARCH_MACOSX_VERSION_MIN make -j$NCPU) || exit 1;
 
 # use the following shell script to build an application bundle
 export MACOSX_DEPLOYMENT_TARGET="${ARCH_MACOSX_VERSION_MIN}"