diff --git a/src/precompiles/ArbOwner.sol b/src/precompiles/ArbOwner.sol
index 42c7a991..4c59e686 100644
--- a/src/precompiles/ArbOwner.sol
+++ b/src/precompiles/ArbOwner.sol
@@ -86,20 +86,18 @@ interface ArbOwner {
     // @notice Releases surplus funds from L1PricerFundsPoolAddress for use
     function releaseL1PricerSurplusFunds(uint256 maxWeiToRelease) external returns (uint256);
 
-    // @notice sets the price (in evm gas basis points) of ink
-    function setInkPrice(uint64 price) external;
+    // @notice sets the amount of ink 1 gas buys
+    // @param price the conversion rate (must fit in a uint24)
+    function setInkPrice(uint32 price) external;
 
     // @notice sets the maximum depth (in wasm words) a wasm stack may grow
     function setWasmMaxDepth(uint32 depth) external;
 
-    // @notice sets the cost of starting a stylus hostio call
-    function setWasmHostioInk(uint64 ink) external;
-
     // @notice sets the number of free wasm pages a tx gets
     function setWasmFreePages(uint16 pages) external;
 
     // @notice sets the base cost of each additional wasm page
-    function setWasmPageGas(uint32 gas) external;
+    function setWasmPageGas(uint16 gas) external;
 
     // @notice sets the ramp that drives exponential wasm memory costs
     function setWasmPageRamp(uint64 ramp) external;
diff --git a/src/precompiles/ArbWasm.sol b/src/precompiles/ArbWasm.sol
index 18dabead..f1a364df 100644
--- a/src/precompiles/ArbWasm.sol
+++ b/src/precompiles/ArbWasm.sol
@@ -12,35 +12,31 @@ interface ArbWasm {
     // @notice compile a wasm program
     // @param program the program to compile
     // @return version the stylus version the program was compiled against
-    function compileProgram(address program) external returns (uint32 version);
+    function compileProgram(address program) external returns (uint16 version);
 
     // @notice gets the latest stylus version
     // @return version the stylus version
-    function stylusVersion() external view returns (uint32 version);
+    function stylusVersion() external view returns (uint16 version);
 
     // @notice gets the stylus version the program was most recently compiled against.
     // @return version the program version (0 for EVM contracts)
-    function programVersion(address program) external view returns (uint32 version);
+    function programVersion(address program) external view returns (uint16 version);
 
     // @notice gets the conversion rate between gas and ink
-    // @return price the price (in evm gas basis points) of ink
-    function inkPrice() external view returns (uint64 price);
+    // @return price the amount of ink 1 gas buys
+    function inkPrice() external view returns (uint32 price);
 
     // @notice gets the wasm stack size limit
     // @return depth the maximum depth (in wasm words) a wasm stack may grow
     function wasmMaxDepth() external view returns (uint32 depth);
 
-    // @notice gets the fixed-cost overhead needed to initiate a hostio call
-    // @return ink the cost of starting a stylus hostio call
-    function wasmHostioInk() external view returns (uint64 ink);
-
     // @notice gets the number of free wasm pages a program gets
     // @return pages the number of wasm pages (2^16 bytes)
     function freePages() external view returns (uint16 pages);
 
     // @notice gets the base cost of each additional wasm page (2^16 bytes)
     // @return gas base amount of gas needed to grow another wasm page
-    function pageGas() external view returns (uint32 gas);
+    function pageGas() external view returns (uint16 gas);
 
     // @notice gets the ramp that drives exponential memory costs
     // @return ramp bits representing the floating point value
@@ -51,6 +47,6 @@ interface ArbWasm {
     function pageLimit() external view returns (uint16 limit);
 
     error ProgramNotCompiled();
-    error ProgramOutOfDate(uint32 version);
+    error ProgramOutOfDate(uint16 version);
     error ProgramUpToDate();
 }