diff --git a/Makefile b/Makefile
index 59b0f28..16273a1 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,9 @@
-# Set to 'yes' to include debugging informations, e.g. DEBUG=yes make -e
+# Set to 'yes' to include debugging information, e.g. DEBUG=yes make -e
 DEBUG		:= no
 
+PREFIX		?= /usr
+LIBDIR		?= lib
+
 # compiler/linker options
 CC		:= gcc
 CFLAGS		:= $(CFLAGS) -Wall -fPIC `pkg-config --cflags libxml-2.0` \
@@ -25,7 +28,7 @@ PAM_USB_SRCS	:= src/pam.c
 PAM_USB_OBJS	:= $(PAM_USB_SRCS:.c=.o)
 PAM_USB			:= pam_usb.so
 PAM_USB_LDFLAGS	:= -shared
-PAM_USB_DEST	:= $(DESTDIR)/lib/security
+PAM_USB_DEST	:= $(DESTDIR)/$(LIBDIR)/security
 
 # pamusb-check
 PAMUSB_CHECK_SRCS	:= src/pamusb-check.c
@@ -35,7 +38,7 @@ PAMUSB_CHECK		:= pamusb-check
 # Tools
 PAMUSB_CONF		:= pamusb-conf
 PAMUSB_AGENT	:= pamusb-agent
-TOOLS_DEST		:= $(DESTDIR)/usr/bin
+TOOLS_DEST		:= $(DESTDIR)$(PREFIX)/bin
 TOOLS_SRC		:= tools
 
 # Conf
@@ -44,11 +47,11 @@ CONFS_DEST		:= $(DESTDIR)/etc
 
 # Doc
 DOCS		:= doc/CONFIGURATION.md
-DOCS_DEST	:= $(DESTDIR)/usr/share/doc/pamusb
+DOCS_DEST	:= $(DESTDIR)$(PREFIX)/share/doc/pamusb
 
 # Man
 MANS		:= doc/pamusb-conf.1.gz doc/pamusb-agent.1.gz doc/pamusb-check.1.gz
-MANS_DEST	:= $(DESTDIR)/usr/share/man/man1
+MANS_DEST	:= $(DESTDIR)$(PREFIX)/share/man/man1
 
 # Binaries
 RM		:= rm
diff --git a/src/conf.h b/src/conf.h
index 07a8810..c43f598 100644
--- a/src/conf.h
+++ b/src/conf.h
@@ -23,7 +23,9 @@
 # define CONF_SERVICE_XPATH "//configuration/services/service[@id='%s']/%s"
 # define CONF_USER_MAXLEN 32
 # include <limits.h>
+#ifdef __linux__
 # include <linux/limits.h>
+#endif
 # include <sys/time.h>
 # ifndef PATH_MAX
 #  define PATH_MAX 4096
diff --git a/src/pad.c b/src/pad.c
index 3074364..1137322 100644
--- a/src/pad.c
+++ b/src/pad.c
@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <fcntl.h>
 #include <pwd.h>
 #include <time.h>
 #include "conf.h"
@@ -73,7 +74,7 @@ static FILE *pusb_pad_open_system(t_pusb_options *opts,
 
 	if (!(user_ent = getpwnam(user)) || !(user_ent->pw_dir))
 	{
-		log_error("Unable to retrieve informations for user \"%s\": %s\n",
+		log_error("Unable to retrieve information for user \"%s\": %s\n",
 				strerror(errno));
 		return (0);
 	}
@@ -111,7 +112,7 @@ static int pusb_pad_protect(const char *user, int fd)
 	log_debug("Protecting pad file...\n");
 	if (!(user_ent = getpwnam(user)))
 	{
-		log_error("Unable to retrieve informations for user \"%s\": %s\n",
+		log_error("Unable to retrieve information for user \"%s\": %s\n",
 				strerror(errno));
 		return (0);
 	}
@@ -181,6 +182,8 @@ static void pusb_pad_update(t_pusb_options *opts,
 	FILE	*f_system = NULL;
 	char	magic[1024];
 	int		i;
+	unsigned int seed;
+	int devrandom;
 
 	if (!pusb_pad_should_update(opts, user))
 		return ;
@@ -201,7 +204,14 @@ static void pusb_pad_update(t_pusb_options *opts,
 	pusb_pad_protect(user, fileno(f_system));
 
 	log_debug("Generating %d bytes unique pad...\n", sizeof(magic));
-	srand(getpid() * time(NULL));
+	devrandom = open("/dev/random", O_RDONLY);
+	if (devrandom < 0 || read(devrandom, &seed, sizeof seed) != sizeof seed) {
+		log_debug("/dev/random seeding failed...\n");
+		seed = getpid() * time(NULL); /* low-entropy fallback */
+	}
+	if (devrandom > 0)
+		close(devrandom);
+	srand(seed);
 	for (i = 0; i < sizeof(magic); ++i)
 		magic[i] = (char)rand();
 	log_debug("Writing pad to the device...\n");
diff --git a/src/volume.c b/src/volume.c
index d54ee72..1b8fe86 100644
--- a/src/volume.c
+++ b/src/volume.c
@@ -21,7 +21,9 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include <sys/types.h>
+#ifndef __GNU__
 #include <sys/mount.h>
+#endif
 #include "mem.h"
 #include "conf.h"
 #include "log.h"