diff --git a/lightningd/Makefile b/lightningd/Makefile
index a5cba0fd2..de338623f 100644
--- a/lightningd/Makefile
+++ b/lightningd/Makefile
@@ -60,6 +60,7 @@ LIGHTNINGD_SRC :=				\
 	lightningd/peer_control.c		\
 	lightningd/peer_htlcs.c			\
 	lightningd/subd.c			\
+	lightningd/txfilter.c			\
 	lightningd/watch.c
 
 # Source files without corresponding headers
@@ -85,7 +86,7 @@ ALL_GEN_HEADERS += $(LIGHTNINGD_HEADERS_GEN)
 # All together in one convenient var
 LIGHTNINGD_HEADERS = $(LIGHTNINGD_HEADERS_NOGEN) $(LIGHTNINGD_HEADERS_GEN) $(EXTERNAL_HEADERS) $(WIRE_HEADERS) $(BITCOIN_HEADERS) $(COMMON_HEADERS) $(WALLET_LIB_HEADERS)
 
-$(LIGHTNINGD_OBJS): $(LIGHTNINGD_HEADERS) 
+$(LIGHTNINGD_OBJS): $(LIGHTNINGD_HEADERS)
 
 lightningd/gen_peer_state_names.h: lightningd/peer_state.h ccan/ccan/cdump/tools/cdump-enumstr
 	ccan/ccan/cdump/tools/cdump-enumstr lightningd/peer_state.h > $@
diff --git a/lightningd/txfilter.c b/lightningd/txfilter.c
new file mode 100644
index 000000000..c0d8552ef
--- /dev/null
+++ b/lightningd/txfilter.c
@@ -0,0 +1,54 @@
+#include "txfilter.h"
+
+#include <bitcoin/script.h>
+#include <ccan/crypto/ripemd160/ripemd160.h>
+#include <common/utils.h>
+
+struct txfilter {
+	u8 **scriptpubkeys;
+};
+
+
+
+struct txfilter *txfilter_new(const tal_t *ctx)
+{
+	struct txfilter *filter = tal(ctx, struct txfilter);
+	filter->scriptpubkeys = tal_arr(filter, u8*, 0);
+	return filter;
+}
+
+static void txfilter_add_scriptpubkey(struct txfilter *filter, u8 *script)
+{
+	size_t count = tal_count(filter->scriptpubkeys);
+	tal_resize(&filter->scriptpubkeys, count + 1);
+	filter->scriptpubkeys[count] = tal_dup_arr(filter, u8, script, tal_len(script), 0);
+}
+
+void txfilter_add_derkey(struct txfilter *filter, u8 derkey[33])
+{
+	tal_t *tmpctx = tal_tmpctx(filter);
+	u8 *skp, *p2sh;
+
+	skp = scriptpubkey_p2wpkh_derkey(tmpctx, derkey);
+	p2sh = scriptpubkey_p2sh(tmpctx, skp);
+
+	txfilter_add_scriptpubkey(filter, take(skp));
+	txfilter_add_scriptpubkey(filter, take(p2sh));
+
+	tal_free(tmpctx);
+}
+
+
+bool txfilter_match(const struct txfilter *filter, const struct bitcoin_tx *tx)
+{
+	u8 *oscript;
+	for (size_t i = 0; i < tal_count(tx->output); i++) {
+		oscript = tx->output[i].script;
+
+		for (size_t j = 0; j < tal_count(filter->scriptpubkeys); j++) {
+			if (scripteq(oscript, filter->scriptpubkeys[j]))
+				return true;
+		}
+	}
+	return false;
+}
diff --git a/lightningd/txfilter.h b/lightningd/txfilter.h
new file mode 100644
index 000000000..a28699e37
--- /dev/null
+++ b/lightningd/txfilter.h
@@ -0,0 +1,30 @@
+#ifndef LIGHTNING_LIGHTNINGD_TXFILTER_H
+#define LIGHTNING_LIGHTNINGD_TXFILTER_H
+#include "config.h"
+#include <bitcoin/tx.h>
+#include <ccan/short_types/short_types.h>
+#include <ccan/tal/tal.h>
+
+struct txfilter;
+
+/**
+ * txfilter_new -- Construct and initialize a new txfilter
+ */
+struct txfilter *txfilter_new(const tal_t *ctx);
+
+/**
+ * txfilter_add_derkey -- Add a scriptpubkeys matching the der key to the filter
+ *
+ * This ensures that we recognize the scriptpubkeys to our keys when
+ * filtering transactions. If any of the outputs matches the
+ * scriptpubkey then the transaction is marked as a match. Adds
+ * scriptpubkey for both raw p2wpkh and p2wpkh wrapped in p2sh.
+ */
+void txfilter_add_derkey(struct txfilter *filter, u8 derkey[33]);
+
+/**
+ * txfilter_match -- Check whether the tx matches the filter
+ */
+bool txfilter_match(const struct txfilter *filter, const struct bitcoin_tx *tx);
+
+#endif /* LIGHTNING_LIGHTNINGD_TXFILTER_H */