diff --git a/src/main.etk b/src/main.etk
index bec086d..37c9e10 100644
--- a/src/main.etk
+++ b/src/main.etk
@@ -39,10 +39,9 @@
         0xfffffffffffffffffffffffffffffffffffffffe
 %end
 
-# get_input loads the first word of input from calldata.
 %macro get_input()
-        %push0()        # [0]
-        calldataload    # [calldata[0..32]]
+        push1 4      # [4]
+        calldataload # [calldata[4:36]]
 %end
 
 # get_timestamp_index calculates the index a timestamp should be stored at.
@@ -52,10 +51,13 @@
         mod             # [timestamp % rootmod]
 %end
 
-%macro revert()
-        %push0()        # [0]
-        %push0()        # [0, 0]
-        revert          # []
+# revert_if_neq reverts if the top two stack arguments are not equal
+# stack: [a, b] (assumed precondition)
+%macro revert_if_neq() 
+        eq              # [a == b]
+        iszero          # [a != b]
+        push1 revert    # [revert, a != b]
+        jumpi           # []
 %end
 
 # -----------------------------------------------------------------------------
@@ -64,7 +66,7 @@
         
 # Protect the submit routine by verifying the caller is equal to sysaddr().
 caller            # [caller]
-push20 sysaddr() # [sysaddr, caller] 
+push20 sysaddr()  # [sysaddr, caller] 
 eq                # [sysaddr == caller]
 push1 submit      # [submitaddr, sysaddr == caller]
 jumpi             # []
@@ -72,19 +74,18 @@ jumpi             # []
 # Fallthrough if addresses don't match -- this means the caller intends to read
 # a root.
 
-# -----------------------------------------------------------------------------
-# READ ROOT -------------------------------------------------------------------
-# -----------------------------------------------------------------------------
-
-# Check if calldata is equal to 32 bytes.
-push1 32        # [32]
-calldatasize    # [calldatasize, 32]
-eq              # [calldatasize == 32]
+# Check if calldata is 36 bytes 
+push1 36        # [36]
+calldatasize    # [calldatasize, 36]
+%revert_if_neq()
 
-# Jump to continue if length-check passed, otherwise revert.
-push1 load      # [load_addr, calldatasize == 32]
-jumpi           # []
-%revert()       # []
+# Check if calldata has the function signature
+push1 0                         # [0]
+calldataload                    # [calldataload]
+push1 224                       # [224, calldataload]
+shr                             # [calldataload >> 224]
+push4 selector("get(uint256)")  # [function_sig, calldataload >> 224]
+%revert_if_neq()
 
 # Load stored timestamp.
 load: 
@@ -96,11 +97,8 @@ dup1            # [time_index, time_index]
 sload           # [timestamp, time_index]
 
 # Verify stored timestamp matches input.
-%get_input()    # [input, timestamp, time_index]
-eq              # [input == timestamp, time_index]
-iszero          # [input != timestamp, time_index]
-push1 exit      # [exit_addr, got != want, time_index]
-jumpi           # [time_index]
+%get_input() # [got, want, time_index]
+%revert_if_neq()
 
 # Extend index to get root index.
 push3 rootmod() # [rootmod, time_index]
@@ -142,3 +140,17 @@ stop                    # []
 # -----------------------------------------------------------------------------
 # SUBMIT END ------------------------------------------------------------------
 # -----------------------------------------------------------------------------
+
+##########
+# REVERT #
+##########
+
+revert:
+jumpdest
+%push0()
+%push0()
+revert
+
+##############
+# REVERT END #
+##############
\ No newline at end of file
diff --git a/test/Contract.t.sol.in b/test/Contract.t.sol.in
index 8f62118..96dee48 100644
--- a/test/Contract.t.sol.in
+++ b/test/Contract.t.sol.in
@@ -33,12 +33,23 @@ contract ContractTest is Test {
         vm.store(unit, timestamp_idx(), timestamp());
         vm.store(unit, root_idx(), root);
 
-        (bool ret, bytes memory data) = unit.call(bytes.concat(timestamp()));
+        (bool ret, bytes memory data) = unit.call(bytes.concat(bytes4(0x9507d39a), bytes32(uint256(block.timestamp))));
 
         assertTrue(ret);
         assertEq(data, bytes.concat(root));
     }
 
+    function testReadWrongSig() public {
+        assertTrue(unit != address(0));
+
+        vm.store(unit, timestamp_idx(), timestamp());
+        vm.store(unit, root_idx(), root);
+
+        (bool ret, /*bytes memory data*/) = unit.call(bytes.concat(bytes4(0x01020304), bytes32(uint256(block.timestamp))));
+        
+        assertFalse(ret);
+    }
+
     function testUpdate() public {
         vm.prank(sysaddr);
         (bool ret, bytes memory data) = unit.call(bytes.concat(root));