diff --git a/qb/qb.libs.sh b/qb/qb.libs.sh
index 8c52ac01c1..93c5d81ed0 100644
--- a/qb/qb.libs.sh
+++ b/qb/qb.libs.sh
@@ -40,7 +40,7 @@ check_lib()	#$1 = HAVE_$1	$2 = lib	$3 = function in lib	$4 = extralibs $5 = head
 	fi
 	answer='no'
 #	echo -n "$ECHOBUF"
-	"$CC" -o "$TEMP_EXE" "$TEMP_C" $INCLUDE_DIRS $LIBRARY_DIRS $4 $CFLAGS $LDFLAGS $2 >>config.log 2>&1 && answer='yes'
+	"$CC" -o "$TEMP_EXE" "$TEMP_C" $INCLUDE_DIRS $LIBRARY_DIRS $(printf %s "$4") $CFLAGS $LDFLAGS $(printf %s "$2") >>config.log 2>&1 && answer='yes'
 	eval HAVE_$1="$answer"; echo "$ECHOBUF ... $answer"
 	rm "$TEMP_C" "$TEMP_EXE" >/dev/null 2>&1
 	
@@ -65,7 +65,7 @@ check_lib_cxx()	#$1 = HAVE_$1	$2 = lib	$3 = function in lib	$4 = extralibs	$5 =
 	fi
 	answer='no'
 #	echo -n "$ECHOBUF"
-	"$CXX" -o "$TEMP_EXE" "$TEMP_CXX" $INCLUDE_DIRS $LIBRARY_DIRS $4 $CFLAGS $LDFLAGS $2 >>config.log 2>&1 && answer='yes'
+	"$CXX" -o "$TEMP_EXE" "$TEMP_CXX" $INCLUDE_DIRS $LIBRARY_DIRS $(printf %s "$4") $CFLAGS $LDFLAGS $(printf %s "$2") >>config.log 2>&1 && answer='yes'
 	eval HAVE_$1="$answer"; echo "$ECHOBUF ... $answer"
 	rm "$TEMP_CXX" "$TEMP_EXE" >/dev/null 2>&1
 	[ "$answer" = 'no' ] && {