diff --git a/sdk/install b/sdk/install
index b77c175..90ee8cf 100755
--- a/sdk/install
+++ b/sdk/install
@@ -66,15 +66,19 @@ case $1 in
     			sed -e 's/__inline//g' -e 's/: \"d0\",/:/g' build/$2/$name.c -i || exit 1
     			echo $3/bin/m68k-amigaos-gcc -Os -noixemul -fomit-frame-pointer build/$2/$name.c -c  
     			$3/bin/m68k-amigaos-gcc -Os -noixemul -fomit-frame-pointer build/$2/$name.c -c -o build/$2/$name.o || exit 1
-    			echo $3/bin/m68k-amigaos-ar r $3/m68k-amigaos/lib/libstubs.a  build/$2/$name.o
-    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libnix/libstubs.a  build/$2/$name.o || exit 1
-    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libm020/libnix/libstubs.a  build/$2/$name.o || exit 1
-    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libm020/libm881/libnix/libstubs.a  build/$2/$name.o || exit 1
-    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb32/libm020/libnix/libstubs.a  build/$2/$name.o || exit 1
-    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb32/libm020/libm881/libnix/libstubs.a  build/$2/$name.o || exit 1
-    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb/libnix/libstubs.a  build/$2/$name.o || exit 1
-    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb/libm020/libnix/libstubs.a  build/$2/$name.o || exit 1
-    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb/libm020/libm881/libnix/libstubs.a  build/$2/$name.o || exit 1
+    			echo $3/bin/m68k-amigaos-ar r $3/m68k-amigaos/lib/libstubs.a build/$2/$name.o
+    			(
+					flock -x 200
+
+	    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libnix/libstubs.a build/$2/$name.o || exit 1
+	    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libm020/libnix/libstubs.a build/$2/$name.o || exit 1
+	    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libm020/libm881/libnix/libstubs.a build/$2/$name.o || exit 1
+	    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb32/libm020/libnix/libstubs.a build/$2/$name.o || exit 1
+	    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb32/libm020/libm881/libnix/libstubs.a build/$2/$name.o || exit 1
+	    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb/libnix/libstubs.a build/$2/$name.o || exit 1
+	    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb/libm020/libnix/libstubs.a build/$2/$name.o || exit 1
+	    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/libnix/lib/libb/libm020/libm881/libnix/libstubs.a build/$2/$name.o || exit 1
+	    		) 200>/tmp/amiga-gcc-libstubs-lock
     		;;
     		lib)
     			sfd=${a[1]}
@@ -84,8 +88,8 @@ case $1 in
     			sed -e 's/__inline//g' -e 's/: \"d0\",/:/g' build/$2/lib$2.c -i || exit 1
     			echo $3/bin/m68k-amigaos-gcc -Os -noixemul -fomit-frame-pointer build/$2/lib$2.c -c 
     			$3/bin/m68k-amigaos-gcc -Os -noixemul -fomit-frame-pointer build/$2/lib$2.c -c -o build/$2/lib$2.o || exit 1
-    			echo $3/bin/m68k-amigaos-ar r $3/m68k-amigaos/lib/lib$2.a  build/$2/lib$2.o
-    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/lib/lib$2.a  build/$2/lib$2.o || exit 1
+    			echo $3/bin/m68k-amigaos-ar r $3/m68k-amigaos/lib/lib$2.a build/$2/lib$2.o
+    			$3/bin/m68k-amigaos-ar r $3/m68k-amigaos/lib/lib$2.a build/$2/lib$2.o || exit 1
     		;;	
     		*)
     			if [ "$line" != "" ]; then