diff --git a/common/fee_states.c b/common/fee_states.c
index 1626ea824c0b..abbf56d920b9 100644
--- a/common/fee_states.c
+++ b/common/fee_states.c
@@ -175,8 +175,12 @@ u32 marginal_feerate(u32 current_feerate)
 	/* This could happen in future if we celebrate sub-sat summer! */
 	if (current_feerate < minfeerate)
 		current_feerate = minfeerate;
-	if (current_feerate > maxfeerate)
-		return current_feerate * 1.1;
+	if (current_feerate > maxfeerate) {
+		u64 marginal = ((u64)current_feerate * 11) / 10;
+		if (marginal > UINT32_MAX)
+			return UINT32_MAX;
+		return marginal;
+	}
 
 	/* min gives 1, max gives 0.1 */
 	double proportion = 1.0 - ((double)current_feerate - minfeerate) / (maxfeerate - minfeerate) * 0.9;
diff --git a/common/test/run-marginal_feerate.c b/common/test/run-marginal_feerate.c
index e0d0ebd4ab72..f693980d75eb 100644
--- a/common/test/run-marginal_feerate.c
+++ b/common/test/run-marginal_feerate.c
@@ -127,5 +127,12 @@ int main(int argc, char *argv[])
 	u32 half = (45000 + 253)/2;
 	assert(marginal_feerate(half) == (u32)(half * 1.55));
 
+	/* These values straddle the case where adding 10% exceeds UINT32_MAX.
+	 * No overflow should occur. */
+	assert(marginal_feerate(3904515722) == UINT32_MAX - 1);
+	assert(marginal_feerate(3904515723) == UINT32_MAX);
+	assert(marginal_feerate(3904515724) == UINT32_MAX);
+	assert(marginal_feerate(UINT32_MAX) == UINT32_MAX);
+
 	common_shutdown();
 }