diff --git a/nfq/desync.c b/nfq/desync.c
index 06196b7..f61d982 100644
--- a/nfq/desync.c
+++ b/nfq/desync.c
@@ -367,7 +367,8 @@ static void auto_hostlist_failed(struct desync_profile *dp, const char *hostname
 				DLOG_PERROR("write to auto hostlist:");
 				return;
 			}
-			dp->hostlist_auto->mod_time = file_mod_time(dp->hostlist_auto->filename);
+			if (!file_mod_signature(dp->hostlist_auto->filename, &dp->hostlist_auto->mod_sig))
+				DLOG_PERROR("file_mod_signature");
 		}
 		else
 		{
diff --git a/nfq/helpers.c b/nfq/helpers.c
index aba018c..03f130c 100644
--- a/nfq/helpers.c
+++ b/nfq/helpers.c
@@ -300,6 +300,14 @@ time_t file_mod_time(const char *filename)
 	struct stat st;
 	return stat(filename,&st)==-1 ? 0 : st.st_mtime;
 }
+bool file_mod_signature(const char *filename, file_mod_sig *ms)
+{
+	struct stat st;
+	if (stat(filename,&st)==-1) return false;
+	ms->mod_time=st.st_mtime;
+	ms->size=st.st_size;
+	return true;
+}
 
 bool pf_in_range(uint16_t port, const port_filter *pf)
 {
diff --git a/nfq/helpers.h b/nfq/helpers.h
index 756bab6..5e8e80c 100644
--- a/nfq/helpers.h
+++ b/nfq/helpers.h
@@ -60,6 +60,14 @@ void fill_pattern(uint8_t *buf,size_t bufsize,const void *pattern,size_t patsize
 
 int fprint_localtime(FILE *F);
 
+typedef struct
+{
+	time_t mod_time;
+	off_t size;
+} file_mod_sig;
+#define FILE_MOD_COMPARE(ms1,ms2) (((ms1)->mod_time==(ms2)->mod_time) && ((ms1)->size==(ms2)->size))
+#define FILE_MOD_RESET(ms) memset(ms,0,sizeof(file_mod_sig))
+bool file_mod_signature(const char *filename, file_mod_sig *ms);
 time_t file_mod_time(const char *filename);
 
 typedef struct
diff --git a/nfq/hostlist.c b/nfq/hostlist.c
index 9b75758..34e25cf 100644
--- a/nfq/hostlist.c
+++ b/nfq/hostlist.c
@@ -105,21 +105,21 @@ static bool LoadHostList(struct hostlist_file *hfile)
 {
 	if (hfile->filename)
 	{
-		time_t t = file_mod_time(hfile->filename);
-		if (!t)
+		file_mod_sig fsig;
+		if (!file_mod_signature(hfile->filename, &fsig))
 		{
 			// stat() error
 			DLOG_ERR("cannot access hostlist file '%s'. in-memory content remains unchanged.\n",hfile->filename);
 			return true;
 		}
-		if (t==hfile->mod_time) return true; // up to date
+		if (FILE_MOD_COMPARE(&hfile->mod_sig,&fsig)) return true; // up to date
 		StrPoolDestroy(&hfile->hostlist);
 		if (!AppendHostList(&hfile->hostlist, hfile->filename))
 		{
 			StrPoolDestroy(&hfile->hostlist);
 			return false;
 		}
-		hfile->mod_time=t;
+		hfile->mod_sig=fsig;
 	}
 	return true;
 }
diff --git a/nfq/ipset.c b/nfq/ipset.c
index 86970b0..a4d1ebe 100644
--- a/nfq/ipset.c
+++ b/nfq/ipset.c
@@ -126,21 +126,21 @@ static bool LoadIpset(struct ipset_file *hfile)
 {
 	if (hfile->filename)
 	{
-		time_t t = file_mod_time(hfile->filename);
-		if (!t)
+		file_mod_sig fsig;
+		if (!file_mod_signature(hfile->filename, &fsig))
 		{
 			// stat() error
 			DLOG_ERR("cannot access ipset file '%s'. in-memory content remains unchanged.\n",hfile->filename);
 			return true;
 		}
-			if (t==hfile->mod_time) return true; // up to date
+		if (FILE_MOD_COMPARE(&hfile->mod_sig,&fsig)) return true; // up to date
 		ipsetDestroy(&hfile->ipset);
 		if (!AppendIpset(&hfile->ipset, hfile->filename))
 		{
 			ipsetDestroy(&hfile->ipset);
 			return false;
 		}
-		hfile->mod_time=t;
+		hfile->mod_sig=fsig;
 	}
 	return true;
 }
diff --git a/nfq/pools.c b/nfq/pools.c
index ac9cb14..4cce2f6 100644
--- a/nfq/pools.c
+++ b/nfq/pools.c
@@ -169,7 +169,7 @@ struct hostlist_file *hostlist_files_add(struct hostlist_files_head *head, const
 		}
 		else
 			entry->filename = NULL;
-		entry->mod_time = 0;
+		FILE_MOD_RESET(&entry->mod_sig);
 		entry->hostlist = NULL;
 		LIST_INSERT_HEAD(head, entry, next);
 	}
@@ -206,7 +206,7 @@ void hostlist_files_reset_modtime(struct hostlist_files_head *list)
 	struct hostlist_file *hfile;
 
 	LIST_FOREACH(hfile, list, next)
-		hfile->mod_time=0;
+		FILE_MOD_RESET(&hfile->mod_sig);
 }
 
 struct hostlist_item *hostlist_collection_add(struct hostlist_collection_head *head, struct hostlist_file *hfile)
@@ -390,7 +390,7 @@ struct ipset_file *ipset_files_add(struct ipset_files_head *head, const char *fi
 		}
 		else
 			entry->filename = NULL;
-		entry->mod_time = 0;
+		FILE_MOD_RESET(&entry->mod_sig);
 		memset(&entry->ipset,0,sizeof(entry->ipset));
 		LIST_INSERT_HEAD(head, entry, next);
 	}
@@ -427,7 +427,7 @@ void ipset_files_reset_modtime(struct ipset_files_head *list)
 	struct ipset_file *hfile;
 
 	LIST_FOREACH(hfile, list, next)
-		hfile->mod_time=0;
+		FILE_MOD_RESET(&hfile->mod_sig);
 }
 
 struct ipset_item *ipset_collection_add(struct ipset_collection_head *head, struct ipset_file *hfile)
diff --git a/nfq/pools.h b/nfq/pools.h
index 41bf1d6..aeda63f 100644
--- a/nfq/pools.h
+++ b/nfq/pools.h
@@ -50,7 +50,7 @@ void strlist_destroy(struct str_list_head *head);
 
 struct hostlist_file {
 	char *filename;
-	time_t mod_time;
+	file_mod_sig mod_sig;
 	strpool *hostlist;
 	LIST_ENTRY(hostlist_file) next;
 };
@@ -112,7 +112,7 @@ void ipsetPrint(ipset *ipset);
 
 struct ipset_file {
 	char *filename;
-	time_t mod_time;
+	file_mod_sig mod_sig;
 	ipset ipset;
 	LIST_ENTRY(ipset_file) next;
 };
diff --git a/tpws/helpers.c b/tpws/helpers.c
index 8d71403..b4f4ba3 100644
--- a/tpws/helpers.c
+++ b/tpws/helpers.c
@@ -314,6 +314,14 @@ time_t file_mod_time(const char *filename)
 	struct stat st;
 	return stat(filename, &st) == -1 ? 0 : st.st_mtime;
 }
+bool file_mod_signature(const char *filename, file_mod_sig *ms)
+{
+	struct stat st;
+	if (stat(filename,&st)==-1) return false;
+	ms->mod_time=st.st_mtime;
+	ms->size=st.st_size;
+	return true;
+}
 
 bool pf_in_range(uint16_t port, const port_filter *pf)
 {
diff --git a/tpws/helpers.h b/tpws/helpers.h
index 3c8a372..1b74430 100644
--- a/tpws/helpers.h
+++ b/tpws/helpers.h
@@ -62,6 +62,14 @@ static inline void phton16(uint8_t *p, uint16_t v) {
 
 int fprint_localtime(FILE *F);
 
+typedef struct
+{
+	time_t mod_time;
+	off_t size;
+} file_mod_sig;
+#define FILE_MOD_COMPARE(ms1,ms2) (((ms1)->mod_time==(ms2)->mod_time) && ((ms1)->size==(ms2)->size))
+#define FILE_MOD_RESET(ms) memset(ms,0,sizeof(file_mod_sig))
+bool file_mod_signature(const char *filename, file_mod_sig *ms);
 time_t file_mod_time(const char *filename);
 
 typedef struct
diff --git a/tpws/hostlist.c b/tpws/hostlist.c
index 6fbbd7d..c10aca6 100644
--- a/tpws/hostlist.c
+++ b/tpws/hostlist.c
@@ -105,21 +105,21 @@ static bool LoadHostList(struct hostlist_file *hfile)
 {
 	if (hfile->filename)
 	{
-		time_t t = file_mod_time(hfile->filename);
-		if (!t)
+		file_mod_sig fsig;
+		if (!file_mod_signature(hfile->filename, &fsig))
 		{
 			// stat() error
 			DLOG_ERR("cannot access hostlist file '%s'. in-memory content remains unchanged.\n",hfile->filename);
 			return true;
 		}
-		if (t==hfile->mod_time) return true; // up to date
+		if (FILE_MOD_COMPARE(&hfile->mod_sig,&fsig)) return true; // up to date
 		StrPoolDestroy(&hfile->hostlist);
 		if (!AppendHostList(&hfile->hostlist, hfile->filename))
 		{
 			StrPoolDestroy(&hfile->hostlist);
 			return false;
 		}
-		hfile->mod_time=t;
+		hfile->mod_sig=fsig;
 	}
 	return true;
 }
diff --git a/tpws/ipset.c b/tpws/ipset.c
index b803205..b486eb4 100644
--- a/tpws/ipset.c
+++ b/tpws/ipset.c
@@ -126,21 +126,21 @@ static bool LoadIpset(struct ipset_file *hfile)
 {
 	if (hfile->filename)
 	{
-		time_t t = file_mod_time(hfile->filename);
-		if (!t)
+		file_mod_sig fsig;
+		if (!file_mod_signature(hfile->filename, &fsig))
 		{
 			// stat() error
 			DLOG_ERR("cannot access ipset file '%s'. in-memory content remains unchanged.\n",hfile->filename);
 			return true;
 		}
-			if (t==hfile->mod_time) return true; // up to date
+		if (FILE_MOD_COMPARE(&hfile->mod_sig,&fsig)) return true; // up to date
 		ipsetDestroy(&hfile->ipset);
 		if (!AppendIpset(&hfile->ipset, hfile->filename))
 		{
 			ipsetDestroy(&hfile->ipset);
 			return false;
 		}
-		hfile->mod_time=t;
+		hfile->mod_sig=fsig;
 	}
 	return true;
 }
diff --git a/tpws/pools.c b/tpws/pools.c
index ac9cb14..4cce2f6 100644
--- a/tpws/pools.c
+++ b/tpws/pools.c
@@ -169,7 +169,7 @@ struct hostlist_file *hostlist_files_add(struct hostlist_files_head *head, const
 		}
 		else
 			entry->filename = NULL;
-		entry->mod_time = 0;
+		FILE_MOD_RESET(&entry->mod_sig);
 		entry->hostlist = NULL;
 		LIST_INSERT_HEAD(head, entry, next);
 	}
@@ -206,7 +206,7 @@ void hostlist_files_reset_modtime(struct hostlist_files_head *list)
 	struct hostlist_file *hfile;
 
 	LIST_FOREACH(hfile, list, next)
-		hfile->mod_time=0;
+		FILE_MOD_RESET(&hfile->mod_sig);
 }
 
 struct hostlist_item *hostlist_collection_add(struct hostlist_collection_head *head, struct hostlist_file *hfile)
@@ -390,7 +390,7 @@ struct ipset_file *ipset_files_add(struct ipset_files_head *head, const char *fi
 		}
 		else
 			entry->filename = NULL;
-		entry->mod_time = 0;
+		FILE_MOD_RESET(&entry->mod_sig);
 		memset(&entry->ipset,0,sizeof(entry->ipset));
 		LIST_INSERT_HEAD(head, entry, next);
 	}
@@ -427,7 +427,7 @@ void ipset_files_reset_modtime(struct ipset_files_head *list)
 	struct ipset_file *hfile;
 
 	LIST_FOREACH(hfile, list, next)
-		hfile->mod_time=0;
+		FILE_MOD_RESET(&hfile->mod_sig);
 }
 
 struct ipset_item *ipset_collection_add(struct ipset_collection_head *head, struct ipset_file *hfile)
diff --git a/tpws/pools.h b/tpws/pools.h
index 41bf1d6..aeda63f 100644
--- a/tpws/pools.h
+++ b/tpws/pools.h
@@ -50,7 +50,7 @@ void strlist_destroy(struct str_list_head *head);
 
 struct hostlist_file {
 	char *filename;
-	time_t mod_time;
+	file_mod_sig mod_sig;
 	strpool *hostlist;
 	LIST_ENTRY(hostlist_file) next;
 };
@@ -112,7 +112,7 @@ void ipsetPrint(ipset *ipset);
 
 struct ipset_file {
 	char *filename;
-	time_t mod_time;
+	file_mod_sig mod_sig;
 	ipset ipset;
 	LIST_ENTRY(ipset_file) next;
 };
diff --git a/tpws/tamper.c b/tpws/tamper.c
index 7492728..c06613e 100644
--- a/tpws/tamper.c
+++ b/tpws/tamper.c
@@ -443,7 +443,8 @@ static void auto_hostlist_failed(struct desync_profile *dp, const char *hostname
 				DLOG_PERROR("write to auto hostlist:");
 				return;
 			}
-			dp->hostlist_auto->mod_time = file_mod_time(dp->hostlist_auto->filename);
+			if (!file_mod_signature(dp->hostlist_auto->filename, &dp->hostlist_auto->mod_sig))
+				DLOG_PERROR("file_mod_signature");
 		}
 		else
 		{