diff --git a/README.md b/README.md
index dbba5db..7f5ea3b 100644
--- a/README.md
+++ b/README.md
@@ -3195,9 +3195,10 @@ Currently supported:
   amount, as of a V4 exact-out step); and one whose amount the decoder does not
   know. When the step that sets the input side states no amount and there is no
   `Amount` line, that step gets them too whenever another take's lines give a
-  figure, so that figure cannot read as all that leaves. They come in step
-  order, the step that sets the input side first when it has them:
-  `Moved from the sender`, its amount, worded as the `Amount` line words one, or
+  figure, or a `PERMIT2_TRANSFER_FROM` of its token gets the lines below, so
+  that figure cannot read as all that leaves. They come in step order, the step
+  that sets the input side first when it has them: `Moved from the sender`, its
+  amount, worded as the `Amount` line words one, or
   `Unknown (could not be decoded)` when the decoder does not know it;
   `Token moved`, giving the token's address as the `Token In` line does; and
   `Moved to`, which reads `The swap step that spends it`. A token the decoder
diff --git a/src/shared/uniswap.js b/src/shared/uniswap.js
index 6563f62..cc1bd83 100644
--- a/src/shared/uniswap.js
+++ b/src/shared/uniswap.js
@@ -1873,14 +1873,18 @@ function decode(data, toAddress, chainId, sources, fromAddress) {
             if (ofTokenIn && !present(t.amount)) total = null;
         }
         inputAmount = permitStands ? permit.amount : total;
-        // With no Amount figure, a later take's own figure could read as all
-        // that leaves, so the step that set the input side, when it stated
-        // no amount, then gets lines of its own too, first, saying its amount
+        // With no Amount figure, a later take's own figure, or that of a
+        // PERMIT2_TRANSFER_FROM of the same token, could read as all that
+        // leaves, so the step that set the input side, when it stated no
+        // amount, then gets lines of its own too, first, saying its amount
         // is not known.
         if (
             !present(inputAmount) &&
             firstTakeUnstated !== null &&
-            spentFromSender.some((s) => present(s.amount))
+            (spentFromSender.some((s) => present(s.amount)) ||
+                movedFromSender.some((m) =>
+                    sameAddress(m.token, firstTakeUnstated.token),
+                ))
         ) {
             spentFromSender.unshift(firstTakeUnstated);
         }
diff --git a/tests/uniswap.test.js b/tests/uniswap.test.js
index 1ae22e6..f896178 100644
--- a/tests/uniswap.test.js
+++ b/tests/uniswap.test.js
@@ -2423,6 +2423,56 @@ describe("uniswap decoder", () => {
             },
         );
 
+        // https://git.eeqj.de/sneak/AutistMask/issues/634 — a
+        // PERMIT2_TRANSFER_FROM of the token the V4 exact-out step spends,
+        // before or after it, shows its own figure, so the step's amount is
+        // shown as not known beside it, and the 400 USDT cannot read as all
+        // that leaves. On next only the 400 USDT was shown.
+        const transferTo = (token, amount) =>
+            coder.encode(
+                ["address", "address", "uint160"],
+                [token, OTHER_ADDR, amount],
+            );
+        const MOVED_400_USDT = [
+            ["Moved from the sender", "400.0000 USDT"],
+            ["Token moved", "USDT (" + USDT_ADDR + ")"],
+            ["Moved to", OTHER_ADDR],
+        ];
+        test.each([
+            {
+                kind: "a V4 exact-out step of at most 600 USDT, then a PERMIT2_TRANSFER_FROM of 400 USDT to another address",
+                commands: [0x10, 0x02],
+                inputs: [V4_EXACT_OUT_600, transferTo(USDT_ADDR, USDT_400)],
+            },
+            {
+                kind: "a PERMIT2_TRANSFER_FROM of 400 USDT to another address, then a V4 exact-out step of at most 600 USDT",
+                commands: [0x02, 0x10],
+                inputs: [transferTo(USDT_ADDR, USDT_400), V4_EXACT_OUT_600],
+            },
+        ])(
+            "$kind, paid by the user, shows that the step's amount is not known",
+            ({ commands, inputs }) => {
+                const result = decodeSteps(commands, inputs);
+                expect(linesBetweenTokens(result)).toEqual([
+                    ...UNKNOWN_USDT,
+                    ...MOVED_400_USDT,
+                ]);
+            },
+        );
+
+        // A move of another token says nothing of how much USDT leaves.
+        test("a V4 exact-out step of at most 600 USDT, then a PERMIT2_TRANSFER_FROM of 400 DAI, shows only the DAI moved", () => {
+            const result = decodeSteps(
+                [0x10, 0x02],
+                [V4_EXACT_OUT_600, transferTo(DAI_ADDR, DAI_400)],
+            );
+            expect(linesBetweenTokens(result)).toEqual([
+                ["Moved from the sender", "400.0000 DAI"],
+                ["Token moved", "DAI (" + DAI_ADDR + ")"],
+                ["Moved to", OTHER_ADDR],
+            ]);
+        });
+
         // A V2 exact-out step makes every amount the swap steps spend a maximum,
         // the total included.
         test("a split with a V2 exact-out step the user pays for shows the total as a maximum", () => {