5 files changed, 10 insertions, 10 deletions
diff --git a/packages/utils/package.json b/packages/utils/package.json
index 315f5a08f..3b16550a5 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -48,7 +48,7 @@
         "@0x/typescript-typings": "^3.0.8",
         "@types/node": "*",
         "abortcontroller-polyfill": "^1.1.9",
-        "bignumber.js": "~4.1.0",
+        "bignumber.js": "~8.0.2",
         "chalk": "^2.4.1",
         "detect-node": "2.0.3",
         "ethereum-types": "^1.1.6",
diff --git a/packages/utils/src/abi_encoder/evm_data_types/bool.ts b/packages/utils/src/abi_encoder/evm_data_types/bool.ts
index 7f91f34e6..23298bc88 100644
--- a/packages/utils/src/abi_encoder/evm_data_types/bool.ts
+++ b/packages/utils/src/abi_encoder/evm_data_types/bool.ts
@@ -37,11 +37,11 @@ export class BoolDataType extends AbstractBlobDataType {
         const valueBuf = calldata.popWord();
         const valueHex = ethUtil.bufferToHex(valueBuf);
         const valueNumber = new BigNumber(valueHex, constants.HEX_BASE);
-        if (!(valueNumber.equals(0) || valueNumber.equals(1))) {
+        if (!(valueNumber.isEqualTo(0) || valueNumber.isEqualTo(1))) {
             throw new Error(`Failed to decode boolean. Expected 0x0 or 0x1, got ${valueHex}`);
         }
         /* tslint:disable boolean-naming */
-        const value: boolean = !valueNumber.equals(0);
+        const value: boolean = !valueNumber.isEqualTo(0);
         /* tslint:enable boolean-naming */
         return value;
     }
diff --git a/packages/utils/src/abi_encoder/evm_data_types/int.ts b/packages/utils/src/abi_encoder/evm_data_types/int.ts
index 8d98e195b..b7e0d9f4e 100644
--- a/packages/utils/src/abi_encoder/evm_data_types/int.ts
+++ b/packages/utils/src/abi_encoder/evm_data_types/int.ts
@@ -38,8 +38,8 @@ export class IntDataType extends AbstractBlobDataType {
             throw new Error(`Tried to instantiate Int with bad input: ${dataItem}`);
         }
         this._width = IntDataType._decodeWidthFromType(dataItem.type);
-        this._minValue = new BigNumber(2).toPower(this._width - 1).times(-1);
-        this._maxValue = new BigNumber(2).toPower(this._width - 1).sub(1);
+        this._minValue = new BigNumber(2).exponentiatedBy(this._width - 1).times(-1);
+        this._maxValue = new BigNumber(2).exponentiatedBy(this._width - 1).minus(1);
     }
 
     public encodeValue(value: BigNumber | string | number): Buffer {
diff --git a/packages/utils/src/abi_encoder/evm_data_types/uint.ts b/packages/utils/src/abi_encoder/evm_data_types/uint.ts
index 8e382e8dc..a82aa789e 100644
--- a/packages/utils/src/abi_encoder/evm_data_types/uint.ts
+++ b/packages/utils/src/abi_encoder/evm_data_types/uint.ts
@@ -38,7 +38,7 @@ export class UIntDataType extends AbstractBlobDataType {
             throw new Error(`Tried to instantiate UInt with bad input: ${dataItem}`);
         }
         this._width = UIntDataType._decodeWidthFromType(dataItem.type);
-        this._maxValue = new BigNumber(2).toPower(this._width).sub(1);
+        this._maxValue = new BigNumber(2).exponentiatedBy(this._width).minus(1);
     }
 
     public encodeValue(value: BigNumber | string | number): Buffer {
diff --git a/packages/utils/src/abi_encoder/utils/math.ts b/packages/utils/src/abi_encoder/utils/math.ts
index d84983c5b..b2fa5fe7d 100644
--- a/packages/utils/src/abi_encoder/utils/math.ts
+++ b/packages/utils/src/abi_encoder/utils/math.ts
@@ -10,9 +10,9 @@ function sanityCheckBigNumberRange(
     maxValue: BigNumber,
 ): void {
     const value = new BigNumber(value_, 10);
-    if (value.greaterThan(maxValue)) {
+    if (value.isGreaterThan(maxValue)) {
         throw new Error(`Tried to assign value of ${value}, which exceeds max value of ${maxValue}`);
-    } else if (value.lessThan(minValue)) {
+    } else if (value.isLessThan(minValue)) {
         throw new Error(`Tried to assign value of ${value}, which exceeds min value of ${minValue}`);
     }
 }
@@ -30,7 +30,7 @@ function bigNumberToPaddedBuffer(value: BigNumber): Buffer {
 export function encodeNumericValue(value_: BigNumber | string | number): Buffer {
     const value = new BigNumber(value_, 10);
     // Case 1/2: value is non-negative
-    if (value.greaterThanOrEqualTo(0)) {
+    if (value.isGreaterThanOrEqualTo(0)) {
         const encodedPositiveValue = bigNumberToPaddedBuffer(value);
         return encodedPositiveValue;
     }
@@ -74,7 +74,7 @@ export function decodeNumericValue(encodedValue: Buffer, minValue: BigNumber): B
     const valueHex = ethUtil.bufferToHex(encodedValue);
     // Case 1/3: value is definitely non-negative because of numeric boundaries
     const value = new BigNumber(valueHex, constants.HEX_BASE);
-    if (!minValue.lessThan(0)) {
+    if (!minValue.isLessThan(0)) {
         return value;
     }
     // Case 2/3: value is non-negative because there is no leading 1 (encoded as two's-complement)