diff --git a/src/rpc/estimation/gasEstimationHandler.ts b/src/rpc/estimation/gasEstimationHandler.ts
index cd87753d..f42c87a9 100644
--- a/src/rpc/estimation/gasEstimationHandler.ts
+++ b/src/rpc/estimation/gasEstimationHandler.ts
@@ -1,4 +1,4 @@
-import type { UserOperation } from "@alto/types"
+import type { ChainType, UserOperation } from "@alto/types"
 import type { StateOverrides, UserOperationV07 } from "@alto/types"
 import type { Hex } from "viem"
 import type { SimulateHandleOpResult } from "./types"
@@ -56,6 +56,7 @@ export class GasEstimationHandler {
         chainId: number,
         blockTagSupport: boolean,
         utilityWalletAddress: Address,
+        chainType: ChainType,
         entryPointSimulationsAddress?: Address,
         fixedGasLimitForEstimation?: bigint
     ) {
@@ -74,6 +75,7 @@ export class GasEstimationHandler {
             entryPointSimulationsAddress,
             blockTagSupport,
             utilityWalletAddress,
+            chainType,
             fixedGasLimitForEstimation
         )
     }
diff --git a/src/rpc/estimation/gasEstimationsV07.ts b/src/rpc/estimation/gasEstimationsV07.ts
index b0893b4a..09feb505 100644
--- a/src/rpc/estimation/gasEstimationsV07.ts
+++ b/src/rpc/estimation/gasEstimationsV07.ts
@@ -22,7 +22,8 @@ import {
     ValidationErrors,
     ExecutionErrors,
     targetCallResultSchema,
-    RpcError
+    RpcError,
+    ChainType
 } from "@alto/types"
 import { getUserOperationHash, toPackedUserOperation } from "@alto/utils"
 import {
@@ -40,6 +41,7 @@ export class GasEstimatorV07 {
     blockTagSupport: boolean
     utilityWalletAddress: Address
     fixedGasLimitForEstimation?: bigint
+    chainType: ChainType
 
     constructor(
         binarySearchToleranceDelta: bigint,
@@ -49,6 +51,7 @@ export class GasEstimatorV07 {
         entryPointSimulationsAddress: Address | undefined,
         blockTagSupport: boolean,
         utilityWalletAddress: Address,
+        chainType: ChainType,
         fixedGasLimitForEstimation?: bigint
     ) {
         this.binarySearchToleranceDelta = binarySearchToleranceDelta
@@ -58,6 +61,7 @@ export class GasEstimatorV07 {
         this.entryPointSimulationsAddress = entryPointSimulationsAddress
         this.blockTagSupport = blockTagSupport
         this.utilityWalletAddress = utilityWalletAddress
+        this.chainType = chainType
         this.fixedGasLimitForEstimation = fixedGasLimitForEstimation
     }
 
@@ -302,14 +306,35 @@ export class GasEstimatorV07 {
             queuedUserOperations
         })
 
-        let cause = await this.callPimlicoEntryPointSimulations({
-            entryPoint,
-            entryPointSimulationsCallData: [
-                simulateHandleOpLast,
-                simulateCallData
-            ],
-            stateOverrides
-        })
+        let cause
+
+        if (this.chainType === "hedera") {
+            // due to Hedera specific restrictions, we can't combine these two calls.
+            const [simulateHandleOpLastCause, simulateCallDataCause] =
+                await Promise.all([
+                    this.callPimlicoEntryPointSimulations({
+                        entryPoint,
+                        entryPointSimulationsCallData: [simulateHandleOpLast],
+                        stateOverrides
+                    }),
+                    this.callPimlicoEntryPointSimulations({
+                        entryPoint,
+                        entryPointSimulationsCallData: [simulateCallData],
+                        stateOverrides
+                    })
+                ])
+
+            cause = [simulateHandleOpLastCause[0], simulateCallDataCause[0]]
+        } else {
+            cause = await this.callPimlicoEntryPointSimulations({
+                entryPoint,
+                entryPointSimulationsCallData: [
+                    simulateHandleOpLast,
+                    simulateCallData
+                ],
+                stateOverrides
+            })
+        }
 
         cause = cause.map((data: Hex) => {
             const decodedDelegateAndError = decodeErrorResult({
diff --git a/src/rpc/rpcHandler.ts b/src/rpc/rpcHandler.ts
index 52e4c276..aaac17ba 100644
--- a/src/rpc/rpcHandler.ts
+++ b/src/rpc/rpcHandler.ts
@@ -82,7 +82,7 @@ import {
     slice,
     toFunctionSelector
 } from "viem"
-import { base, baseSepolia, optimism } from "viem/chains"
+import { base, baseSepolia, hedera, optimism } from "viem/chains"
 import type { NonceQueuer } from "./nonceQueuer"
 
 export interface IRpcEndpoint {
@@ -423,6 +423,12 @@ export class RpcHandler implements IRpcEndpoint {
             userOperation.verificationGasLimit = 5_000_000n
         }
 
+        if (this.chainId === hedera.id) {
+            // The eth_call gasLimit is set to 12_500_000 on Hedera.
+            userOperation.verificationGasLimit = 5_000_000n
+            userOperation.callGasLimit = 4_500_000n
+        }
+
         if (isVersion07(userOperation)) {
             userOperation.paymasterPostOpGasLimit = 2_000_000n
             userOperation.paymasterVerificationGasLimit = 5_000_000n
diff --git a/src/rpc/validation/UnsafeValidator.ts b/src/rpc/validation/UnsafeValidator.ts
index 672de353..375d3ac1 100644
--- a/src/rpc/validation/UnsafeValidator.ts
+++ b/src/rpc/validation/UnsafeValidator.ts
@@ -96,6 +96,7 @@ export class UnsafeValidator implements InterfaceValidator {
             publicClient.chain.id,
             blockTagSupport,
             utilityWalletAddress,
+            chainType,
             entryPointSimulationsAddress,
             fixedGasLimitForEstimation
         )