diff --git a/funding.c b/funding.c
index 2f536b13a..496814f55 100644
--- a/funding.c
+++ b/funding.c
@@ -1,17 +1,18 @@
 #include "funding.h"
 #include <assert.h>
 
-/* FIXME: Fees! */
 bool funding_delta(const OpenChannel *a,
 		   const OpenChannel *b,
 		   const OpenAnchor *anchor,
+		   uint64_t fee,
 		   uint64_t *channel_delta,
 		   int64_t delta_a_to_b,
 		   uint64_t *a_amount,
 		   uint64_t *b_amount)
 {
-	uint64_t *funder_amount, *non_funder_amount;
+	uint64_t *funder_amount, *non_funder_amount, new_delta;
 	int64_t delta_to_funder;
+	uint64_t funder_fee, non_funder_fee;
 
 	assert(*channel_delta <= anchor->amount);
 
@@ -39,20 +40,58 @@ bool funding_delta(const OpenChannel *a,
 	} else if (-delta_to_funder > anchor->amount - *channel_delta)
 		return false;
 
-	*channel_delta -= delta_to_funder;
-	*funder_amount = anchor->amount - *channel_delta;
-	*non_funder_amount = *channel_delta;
+	new_delta = *channel_delta - delta_to_funder;
+	*funder_amount = anchor->amount - new_delta;
+	*non_funder_amount = new_delta;
+
+	/* We try to split fee. */
+	funder_fee = fee / 2;
+	/* Funder gets any 1 satoshi rounding benefit! */
+	non_funder_fee = fee - funder_fee;
+
+	if (*non_funder_amount < non_funder_fee) {
+		/*
+		 * This happens initially, as funder has all the money.
+		 * That's OK, but don't let non-funder withdraw if they can't
+		 * cover fee.
+		 */
+		if (delta_to_funder > 0)
+			return false;
+
+		/* Pay everything they can, funder pays rest. */
+		non_funder_fee = *non_funder_amount;
+		funder_fee = fee - non_funder_fee;
+	}
+
+	/* Funder must always ensure they can pay their share. */
+	if (*funder_amount < funder_fee)
+		return false;
+
+	*funder_amount -= funder_fee;
+	*non_funder_amount -= non_funder_fee;
+
+	/* Now we know we're succeeding, update caller's channel_delta */
+	*channel_delta = new_delta;
 	return true;
 }
 
 bool initial_funding(const OpenChannel *a,
 		     const OpenChannel *b,
 		     const OpenAnchor *anchor,
+		     uint64_t fee,
 		     uint64_t *a_amount,
 		     uint64_t *b_amount)
 {
 	uint64_t channel_delta = 0;
 
-	return funding_delta(a, b, anchor, &channel_delta, 0,
+	return funding_delta(a, b, anchor, fee, &channel_delta, 0,
 			     a_amount, b_amount);
 }
+
+/* We take the minimum.  If one side offers too little, it should be rejected */
+uint64_t commit_fee(const OpenChannel *a, const OpenChannel *b)
+{
+	if (a->commitment_fee < b->commitment_fee)
+		return a->commitment_fee;
+	return b->commitment_fee;
+}
diff --git a/funding.h b/funding.h
index 5c1c0accb..76b1e3782 100644
--- a/funding.h
+++ b/funding.h
@@ -9,12 +9,14 @@
  * @a: A's openchannel offer
  * @b: B's openchannel offer
  * @anchor: The anchor offer (A or B)
+ * @fee: amount to pay in fees.
  * @a_amount: amount commit tx will output to A.
  * @b_amount: amount commit tx will output to B.
  */
 bool initial_funding(const OpenChannel *a,
 		     const OpenChannel *b,
 		     const OpenAnchor *anchor,
+		     uint64_t fee,
 		     uint64_t *a_amount,
 		     uint64_t *b_amount);
 
@@ -23,6 +25,7 @@ bool initial_funding(const OpenChannel *a,
  * @a: A's openchannel offer
  * @b: B's openchannel offer
  * @anchor: The anchor offer (A or B)
+ * @fee: amount to pay in fees.
  * @channel_delta: In/out amount funder pays to non-funder (channel state)
  * @delta_a_to_b: How much A pays to B (satoshi).
  * @a_amount: amount commit tx will output to A.
@@ -31,9 +34,16 @@ bool initial_funding(const OpenChannel *a,
 bool funding_delta(const OpenChannel *a,
 		   const OpenChannel *b,
 		   const OpenAnchor *anchor,
+		   uint64_t fee,
 		   uint64_t *channel_delta,
 		   int64_t delta_a_to_b,
 		   uint64_t *a_amount,
 		   uint64_t *b_amount);
 
+/**
+ * commit_fee: Fee amount for commit tx.
+ * @a: A's openchannel offer
+ * @b: B's openchannel offer
+ */
+uint64_t commit_fee(const OpenChannel *a, const OpenChannel *b);
 #endif /* LIGHTNING_FUNDING_H */
diff --git a/lightning.pb-c.c b/lightning.pb-c.c
index 49c5060e3..8590f7d4b 100644
--- a/lightning.pb-c.c
+++ b/lightning.pb-c.c
@@ -925,7 +925,7 @@ const ProtobufCEnumDescriptor open_channel__anchor_offer__descriptor =
   NULL,NULL,NULL,NULL   /* reserved[1234] */
 };
 static const uint32_t open_channel__min_depth__default_value = 0u;
-static const ProtobufCFieldDescriptor open_channel__field_descriptors[7] =
+static const ProtobufCFieldDescriptor open_channel__field_descriptors[8] =
 {
   {
     "final_key",
@@ -1011,10 +1011,23 @@ static const ProtobufCFieldDescriptor open_channel__field_descriptors[7] =
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
   },
+  {
+    "commitment_fee",
+    8,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_UINT64,
+    0,   /* quantifier_offset */
+    offsetof(OpenChannel, commitment_fee),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
 };
 static const unsigned open_channel__field_indices_by_name[] = {
   5,   /* field[5] = anch */
   4,   /* field[4] = commit_key */
+  7,   /* field[7] = commitment_fee */
   0,   /* field[0] = final_key */
   2,   /* field[2] = locktime_blocks */
   1,   /* field[1] = locktime_seconds */
@@ -1024,7 +1037,7 @@ static const unsigned open_channel__field_indices_by_name[] = {
 static const ProtobufCIntRange open_channel__number_ranges[1 + 1] =
 {
   { 1, 0 },
-  { 0, 7 }
+  { 0, 8 }
 };
 const ProtobufCMessageDescriptor open_channel__descriptor =
 {
@@ -1034,7 +1047,7 @@ const ProtobufCMessageDescriptor open_channel__descriptor =
   "OpenChannel",
   "",
   sizeof(OpenChannel),
-  7,
+  8,
   open_channel__field_descriptors,
   open_channel__field_indices_by_name,
   1,  open_channel__number_ranges,
diff --git a/lightning.pb-c.h b/lightning.pb-c.h
index 37924b60e..2e1818cbc 100644
--- a/lightning.pb-c.h
+++ b/lightning.pb-c.h
@@ -127,6 +127,10 @@ struct  _OpenChannel
    */
   protobuf_c_boolean has_min_depth;
   uint32_t min_depth;
+  /*
+   * How much fee would I like on commitment tx?
+   */
+  uint64_t commitment_fee;
   OpenChannel__LocktimeCase locktime_case;
   union {
     uint32_t locktime_seconds;
@@ -135,7 +139,7 @@ struct  _OpenChannel
 };
 #define OPEN_CHANNEL__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&open_channel__descriptor) \
-    , NULL, NULL, NULL, 0, 0,0u, OPEN_CHANNEL__LOCKTIME__NOT_SET, {} }
+    , NULL, NULL, NULL, 0, 0,0u, 0, OPEN_CHANNEL__LOCKTIME__NOT_SET, {} }
 
 
 /*
diff --git a/lightning.proto b/lightning.proto
index c4688af55..1cbef50d0 100644
--- a/lightning.proto
+++ b/lightning.proto
@@ -58,6 +58,9 @@ message open_channel {
 
   // How far must anchor be buried before we consider channel live?
   optional uint32 min_depth = 7 [ default = 0 ];
+
+  // How much fee would I like on commitment tx?
+  required uint64 commitment_fee = 8;
 }
 
 // Whoever is supplying anchor sends this.
diff --git a/pkt.c b/pkt.c
index eeffef8fd..de6460213 100644
--- a/pkt.c
+++ b/pkt.c
@@ -37,7 +37,8 @@ struct pkt *open_channel_pkt(const tal_t *ctx,
 			     const struct pubkey *final,
 			     u32 rel_locktime_seconds,
 			     bool offer_anchor,
-			     u32 min_depth)
+			     u32 min_depth,
+			     u64 commitment_fee)
 {
 	OpenChannel o = OPEN_CHANNEL__INIT;
 
@@ -46,6 +47,7 @@ struct pkt *open_channel_pkt(const tal_t *ctx,
 	o.final_key = pubkey_to_proto(ctx, final);
 	o.locktime_case = OPEN_CHANNEL__LOCKTIME_LOCKTIME_SECONDS;
 	o.locktime_seconds = rel_locktime_seconds;
+	o.commitment_fee = commitment_fee;
 	if (offer_anchor)
 		o.anch = OPEN_CHANNEL__ANCHOR_OFFER__WILL_CREATE_ANCHOR;
 	else
diff --git a/pkt.h b/pkt.h
index e081f21df..3e18f2241 100644
--- a/pkt.h
+++ b/pkt.h
@@ -37,6 +37,7 @@ struct pubkey;
  * @rel_locktime_seconds: relative seconds for commitment locktime.
  * @offer_anchor: whether we will offer anchor.
  * @min_depth: minimum depth to insist on (if non-zero)
+ * @commitment_fee: fee we would like for commitment txs.
  */
 struct pkt *open_channel_pkt(const tal_t *ctx,
 			     const struct sha256 *revocation_hash,
@@ -44,7 +45,8 @@ struct pkt *open_channel_pkt(const tal_t *ctx,
 			     const struct pubkey *final,
 			     u32 rel_locktime_seconds,
 			     bool offer_anchor,
-			     u32 min_depth);
+			     u32 min_depth,
+			     u64 commitment_fee);
 
 /**
  * open_anchor_pkt - create an open_anchor message packet
diff --git a/test-cli/check-commit-sig.c b/test-cli/check-commit-sig.c
index 321214134..19b3ef0d2 100644
--- a/test-cli/check-commit-sig.c
+++ b/test-cli/check-commit-sig.c
@@ -68,7 +68,8 @@ int main(int argc, char *argv[])
 	if (!proto_to_pubkey(o2->commit_key, &pubkey2))
 		errx(1, "Invalid o2 commit_key");
 
-	if (!initial_funding(o1, o2, a, &our_amount, &their_amount))
+	if (!initial_funding(o1, o2, a, commit_fee(o1, o2),
+			     &our_amount, &their_amount))
 		errx(1, "Invalid open combination (need 1 anchor offer)");
 	
 	/* Now create our commitment tx. */
diff --git a/test-cli/close-channel.c b/test-cli/close-channel.c
index 03b1af69c..51fddfa5e 100644
--- a/test-cli/close-channel.c
+++ b/test-cli/close-channel.c
@@ -57,7 +57,7 @@ int main(int argc, char *argv[])
 	if (!testnet)
 		errx(1, "Private key '%s' not on testnet!", argv[4]);
 
-	gather_updates(o1, o2, a, argv + 5, &our_amount, &their_amount,
+	gather_updates(o1, o2, a, 0, argv + 5, &our_amount, &their_amount,
 		       NULL, NULL, NULL);
 
 	/* Get pubkeys */
diff --git a/test-cli/create-close-tx.c b/test-cli/create-close-tx.c
index 1c2de558c..894c2b8aa 100644
--- a/test-cli/create-close-tx.c
+++ b/test-cli/create-close-tx.c
@@ -56,7 +56,7 @@ int main(int argc, char *argv[])
 		errx(1, "Invalid o2 commit_key");
 	
 	/* Get delta by accumulting all the updates. */
-	gather_updates(o1, o2, a, argv + 6, &our_amount, &their_amount,
+	gather_updates(o1, o2, a, 0, argv + 6, &our_amount, &their_amount,
 		       NULL, NULL, NULL);
 
 	/* This is what the anchor pays to; figure out which output. */
diff --git a/test-cli/create-commit-spend-tx.c b/test-cli/create-commit-spend-tx.c
index ca3ea2163..d782b147b 100644
--- a/test-cli/create-commit-spend-tx.c
+++ b/test-cli/create-commit-spend-tx.c
@@ -19,6 +19,7 @@
 #include "find_p2sh_out.h"
 #include "protobuf_convert.h"
 #include "test-cli/gather_updates.h"
+#include "funding.h"
 #include <unistd.h>
 
 int main(int argc, char *argv[])
@@ -81,7 +82,8 @@ int main(int argc, char *argv[])
 		errx(1, "Invalid o2 final pubkey");
 
 	/* We use this simply to get final revocation hash. */
-	gather_updates(o1, o2, a, argv + 7, &our_amount, &their_amount,
+	gather_updates(o1, o2, a, commit_fee(o1, o2), argv + 7,
+		       &our_amount, &their_amount,
 		       &rhash, NULL, NULL);
 
 	/* Create redeem script */
diff --git a/test-cli/create-commit-tx.c b/test-cli/create-commit-tx.c
index 7c21c32e4..d52ccfe5d 100644
--- a/test-cli/create-commit-tx.c
+++ b/test-cli/create-commit-tx.c
@@ -16,6 +16,7 @@
 #include "find_p2sh_out.h"
 #include "protobuf_convert.h"
 #include "gather_updates.h"
+#include "funding.h"
 #include <unistd.h>
 
 /* FIXME: this code doesn't work if we're not the ones proposing the delta */
@@ -65,7 +66,8 @@ int main(int argc, char *argv[])
 
 	sig2.stype = SIGHASH_ALL;
 
-	gather_updates(o1, o2, a, argv + 5, &our_amount, &their_amount,
+	gather_updates(o1, o2, a, commit_fee(o1, o2), argv + 5,
+		       &our_amount, &their_amount,
 		       &rhash, NULL, &sig2.sig);
 
 	redeemscript = bitcoin_redeem_2of2(ctx, &pubkey1, &pubkey2);
diff --git a/test-cli/gather_updates.c b/test-cli/gather_updates.c
index 2579e6541..00c19a211 100644
--- a/test-cli/gather_updates.c
+++ b/test-cli/gather_updates.c
@@ -33,7 +33,7 @@ static void get_rhash(const Sha256Hash *rhash, struct sha256 *old,
 
 /* Takes complete update history, gets summary of last state. */
 uint64_t gather_updates(const OpenChannel *o1, const OpenChannel *o2,
-			const OpenAnchor *oa,
+			const OpenAnchor *oa, uint64_t fee,
 			char **argv,
 			uint64_t *our_amount, uint64_t *their_amount,
 			struct sha256 *our_rhash,
@@ -46,7 +46,7 @@ uint64_t gather_updates(const OpenChannel *o1, const OpenChannel *o2,
 	struct sha256 old_our_rhash, old_their_rhash;
 	
 	/* Start sanity check. */
-	if (!initial_funding(o1, o2, oa, our_amount, their_amount))
+	if (!initial_funding(o1, o2, oa, fee, our_amount, their_amount))
 		errx(1, "Invalid open combination (need 1 anchor offer)");
 
 	if (our_rhash)
@@ -88,7 +88,7 @@ uint64_t gather_updates(const OpenChannel *o1, const OpenChannel *o2,
 				get_rhash(pkt->update->revocation_hash,
 					  &old_our_rhash, our_rhash);
 			}
-			if (!funding_delta(o1, o2, oa, &cdelta, delta,
+			if (!funding_delta(o1, o2, oa, fee, &cdelta, delta,
 					   our_amount, their_amount))
 				errx(1, "Impossible funding update %lli %s",
 				     (long long)delta, *argv);
diff --git a/test-cli/gather_updates.h b/test-cli/gather_updates.h
index bfd183dad..57309ffef 100644
--- a/test-cli/gather_updates.h
+++ b/test-cli/gather_updates.h
@@ -6,7 +6,7 @@ struct signature;
 struct sha256;
 
 uint64_t gather_updates(const OpenChannel *o1, const OpenChannel *o2,
-			const OpenAnchor *oa,
+			const OpenAnchor *oa, uint64_t fee,
 			char **argv,
 			uint64_t *our_amount, uint64_t *their_amount,
 			struct sha256 *our_rhash,
diff --git a/test-cli/open-channel.c b/test-cli/open-channel.c
index fe3959994..4f8edfb2d 100644
--- a/test-cli/open-channel.c
+++ b/test-cli/open-channel.c
@@ -29,6 +29,7 @@ int main(int argc, char *argv[])
 	struct pkt *pkt;
 	const tal_t *ctx = tal_arr(NULL, char, 0);
 	unsigned int locktime_seconds, min_confirms;
+	u64 commit_tx_fee;
 	bool offer_anchor = false;
 	struct pubkey commitkey, finalkey;
 
@@ -38,6 +39,8 @@ int main(int argc, char *argv[])
 	locktime_seconds = LOCKTIME_MIN + 24 * 60 * 60;
 	/* Zero, unless they set --offer-anchor or --min-anchor-confirms */
 	min_confirms = 0;
+	/* We only need this for involuntary close, so make it larger. */
+	commit_tx_fee = 100000;
 	
 	opt_register_noarg("--help|-h", opt_usage_and_exit,
 			   "<seed> <commitpubkey> <finalpubkey>\n"
@@ -52,6 +55,9 @@ int main(int argc, char *argv[])
 	opt_register_noarg("--offer-anchor",
 			   opt_set_bool, &offer_anchor,
 			   "Offer to create anchor transaction");
+	opt_register_arg("--commitment-fee=<bits>",
+			 opt_set_bits, opt_show_bits, &commit_tx_fee,
+			 "100's of satoshi to pay for commitment");
 
  	opt_parse(&argc, argv, opt_log_stderr_exit);
 
@@ -76,7 +82,8 @@ int main(int argc, char *argv[])
 	       revocation_hash.u.u8, sizeof(revocation_hash.u.u8));
 
 	pkt = open_channel_pkt(ctx, &revocation_hash, &commitkey, &finalkey,
-			       locktime_seconds, offer_anchor, min_confirms);
+			       locktime_seconds, offer_anchor, min_confirms,
+			       commit_tx_fee);
 
 	if (!write_all(STDOUT_FILENO, pkt, pkt_totlen(pkt)))
 		err(1, "Writing out packet");
diff --git a/test-cli/open-commit-sig.c b/test-cli/open-commit-sig.c
index f3ee3c638..af5f08a74 100644
--- a/test-cli/open-commit-sig.c
+++ b/test-cli/open-commit-sig.c
@@ -55,7 +55,7 @@ int main(int argc, char *argv[])
 		errx(1, "Private key '%s' not on testnet!", argv[4]);
 
 	/* Now create THEIR commitment tx to spend 2/2 output of anchor. */
-	if (!initial_funding(o1, o2, a, &to_us, &to_them))
+	if (!initial_funding(o1, o2, a, commit_fee(o1, o2), &to_us, &to_them))
 		errx(1, "Invalid open combination (need 1 anchor offer)");
 
 	proto_to_sha256(o2->revocation_hash, &rhash);
diff --git a/test-cli/scripts/test.sh b/test-cli/scripts/test.sh
index 62a1d450d..ed8337099 100755
--- a/test-cli/scripts/test.sh
+++ b/test-cli/scripts/test.sh
@@ -114,8 +114,8 @@ B_UPDATE_PKTS="-- +B-commit-sig.pb"
 $PREFIX ./create-commit-tx A-open.pb B-open.pb A-anchor.pb $A_TMPKEY $A_UPDATE_PKTS > A-commit-0.tx
 $PREFIX ./create-commit-tx B-open.pb A-open.pb A-anchor.pb $B_TMPKEY $B_UPDATE_PKTS > B-commit-0.tx
 
-# Now, update the channel, so I pay you 500 satoshi.
-$PREFIX ./update-channel --to-them=500 $A_SEED 1 > A-update-1.pb
+# Now, update the channel, so I pay you 60000 satoshi (covers 50000 fee)
+$PREFIX ./update-channel --to-them=60000 $A_SEED 1 > A-update-1.pb
 A_UPDATE_PKTS="$A_UPDATE_PKTS +A-update-1.pb"
 B_UPDATE_PKTS="$B_UPDATE_PKTS -A-update-1.pb"
 
diff --git a/test-cli/update-channel-accept.c b/test-cli/update-channel-accept.c
index e589b05e4..0120d86e8 100644
--- a/test-cli/update-channel-accept.c
+++ b/test-cli/update-channel-accept.c
@@ -17,6 +17,7 @@
 #include "find_p2sh_out.h"
 #include "protobuf_convert.h"
 #include "gather_updates.h"
+#include "funding.h"
 #include <unistd.h>
 
 int main(int argc, char *argv[])
@@ -60,7 +61,7 @@ int main(int argc, char *argv[])
 		errx(1, "Private key '%s' not on testnet!", argv[5]);
 
 	/* Figure out cumulative delta since anchor. */
-	num_updates = gather_updates(o1, o2, a, argv + 6,
+	num_updates = gather_updates(o1, o2, a, commit_fee(o1, o2), argv + 6,
 				     &our_amount, &their_amount,
 				     NULL, &their_rhash, NULL);
 
diff --git a/test-cli/update-channel-complete.c b/test-cli/update-channel-complete.c
index b709ddaa0..3ccc2f5ae 100644
--- a/test-cli/update-channel-complete.c
+++ b/test-cli/update-channel-complete.c
@@ -56,7 +56,7 @@ int main(int argc, char *argv[])
 	sig.stype = SIGHASH_ALL;
 
 	/* This also checks that preimage is correct! */
-	num_updates = gather_updates(o1, o2, a, argv + 5,
+	num_updates = gather_updates(o1, o2, a, commit_fee(o1, o2), argv + 5,
 				     &our_amount, &their_amount,
 				     &our_rhash, &their_rhash, &sig.sig);
 	if (num_updates < 1)
diff --git a/test-cli/update-channel-signature.c b/test-cli/update-channel-signature.c
index 08f1a0799..734f14866 100644
--- a/test-cli/update-channel-signature.c
+++ b/test-cli/update-channel-signature.c
@@ -17,6 +17,7 @@
 #include "find_p2sh_out.h"
 #include "protobuf_convert.h"
 #include "gather_updates.h"
+#include "funding.h"
 #include <unistd.h>
 
 int main(int argc, char *argv[])
@@ -62,7 +63,7 @@ int main(int argc, char *argv[])
 	sig.stype = SIGHASH_ALL;
 
 	/* Figure out cumulative delta since anchor. */
-	num_updates = gather_updates(o1, o2, a, argv + 6,
+	num_updates = gather_updates(o1, o2, a, commit_fee(o1, o2), argv + 6,
 				     &our_amount, &their_amount,
 				     &our_rhash, &their_rhash, &sig.sig);
 	if (num_updates < 1)