diff --git a/Makefile b/Makefile
index ce40698..1cb031a 100644
--- a/Makefile
+++ b/Makefile
@@ -11,7 +11,7 @@ install : $(PROGRAMS)
 	cp $^ $(HOME)/bin/
 
 dlight : dlight.o buffer.o env.o http.o rss.o lockfile.o filter.o cconf.o \
-	proc-cache.o error.o
+	proc-cache.o dlhist.o error.o
 dlight-compile : compile.o buffer.o env.o lockfile.o filter.o cconf.o error.o
 dlight-read-config : read-config.o buffer.o env.o cconf.o error.o
 dlight-filter-check: filter-check.o filter.o error.o
diff --git a/dlhist.c b/dlhist.c
index 5c5f2c8..e93520d 100644
--- a/dlhist.c
+++ b/dlhist.c
@@ -68,7 +68,7 @@ static unsigned hash(const char *s) {
 
 	unsigned h;
 
-        for(h = 0; *s; s++)
+	for(h = 0; *s; s++)
 		h = ((unsigned)*s) + (h << 6) + (h << 16) - h;
         return h;
 }
@@ -297,7 +297,7 @@ static int path_cmp(const char *a, const char *b) {
 
 	if (stat(a, &sa) < 0 || stat(b, &sb) < 0)
 		return 0;
-	return sa.st_dev == sb.st_dev &&
+	return  sa.st_dev == sb.st_dev &&
 		sa.st_ino == sb.st_ino;
 }
 
diff --git a/dlight.c b/dlight.c
index 31c373e..73885f7 100644
--- a/dlight.c
+++ b/dlight.c
@@ -9,12 +9,14 @@
 #include "env.h"
 #include "error.h"
 #include "cconf.h"
+#include "dlhist.h"
 #include "proc-cache.h"
 #include "filter.h"
 #include "http.h"
 #include "rss.h"
 
 #define PROC_CACHE_PURGE_INTERVAL (60*60*6) /* 6 hours (in seconds) */
+#define DLHIST_PURGE_INTERVAL (60*60*24) /* 1 day */
 
 static int write_http_file(struct http_file *file, const char *dest) {
 
@@ -51,7 +53,8 @@ static void process_items(rss_t rss, struct target *t) {
 		for(i=0; i < t->nr; i++) {
 			struct filter *filter = &t->filter[i];
 
-			if (!filter_match(filter->pattern, item.title))
+			if (dlhist_lookup(item.title, filter->dest) ||
+				!filter_match(filter->pattern, item.title))
 				continue;
 
 			/* fetch the file if we haven't already. */
@@ -70,6 +73,7 @@ static void process_items(rss_t rss, struct target *t) {
 			printf("Downloaded: %s (%s) to %s\n",
 				item.title, item.link, filter->dest);
 
+			dlhist_mark(item.title, filter->dest);
 			proc_cache_update(item.link);
 		}
 
@@ -83,6 +87,7 @@ static void process(struct cconf *config) {
 	struct buffer *data;
 
 	proc_cache_purge(PROC_CACHE_PURGE_INTERVAL);
+	dlhist_purge(DLHIST_PURGE_INTERVAL);
 
 	for(i=0; i < config->nr; i++) {
 		struct target *t = config->target + i;
@@ -118,12 +123,14 @@ int main(int argc, char *argv[]) {
 		return 1;
 	}
 
-	if (proc_cache_open() < 0)
+	/* open process cache and download history. */
+	if (proc_cache_open() < 0 || dlhist_open() < 0)
 		return 1;
 
 	process(config);
 
 	proc_cache_close();
+	dlhist_close();
 	cconf_free(config);
 
 	return 0;