diff --git a/src/util.test.ts b/src/util.test.ts
index 3a9128fe44f..b0c35e827b4 100644
--- a/src/util.test.ts
+++ b/src/util.test.ts
@@ -109,31 +109,31 @@ describe('util', () => {
 
   describe('gweiDecToWEIBN', () => {
     it('should convert a whole number to WEI', () => {
-      expect(util.gweiDecToWEIBN(1).toNumber()).toBe(1000);
-      expect(util.gweiDecToWEIBN(123).toNumber()).toBe(123000);
-      expect(util.gweiDecToWEIBN(101).toNumber()).toBe(101000);
-      expect(util.gweiDecToWEIBN(1234).toNumber()).toBe(1234000);
+      expect(util.gweiDecToWEIBN(1).toNumber()).toBe(1000000000);
+      expect(util.gweiDecToWEIBN(123).toNumber()).toBe(123000000000);
+      expect(util.gweiDecToWEIBN(101).toNumber()).toBe(101000000000);
+      expect(util.gweiDecToWEIBN(1234).toNumber()).toBe(1234000000000);
     });
 
     it('should convert a number with a decimal part to WEI', () => {
-      expect(util.gweiDecToWEIBN(1.1).toNumber()).toBe(1100);
-      expect(util.gweiDecToWEIBN(123.01).toNumber()).toBe(123010);
-      expect(util.gweiDecToWEIBN(101.001).toNumber()).toBe(101001);
-      expect(util.gweiDecToWEIBN(1234.567).toNumber()).toBe(1234567);
+      expect(util.gweiDecToWEIBN(1.1).toNumber()).toBe(1100000000);
+      expect(util.gweiDecToWEIBN(123.01).toNumber()).toBe(123010000000);
+      expect(util.gweiDecToWEIBN(101.001).toNumber()).toBe(101001000000);
+      expect(util.gweiDecToWEIBN(1234.567).toNumber()).toBe(1234567000000);
     });
 
     it('should convert a number < 1 to WEI', () => {
-      expect(util.gweiDecToWEIBN(0.1).toNumber()).toBe(100);
-      expect(util.gweiDecToWEIBN(0.01).toNumber()).toBe(10);
-      expect(util.gweiDecToWEIBN(0.001).toNumber()).toBe(1);
-      expect(util.gweiDecToWEIBN(0.567).toNumber()).toBe(567);
+      expect(util.gweiDecToWEIBN(0.1).toNumber()).toBe(100000000);
+      expect(util.gweiDecToWEIBN(0.01).toNumber()).toBe(10000000);
+      expect(util.gweiDecToWEIBN(0.001).toNumber()).toBe(1000000);
+      expect(util.gweiDecToWEIBN(0.567).toNumber()).toBe(567000000);
     });
 
     it('should round to whole WEI numbers', () => {
-      expect(util.gweiDecToWEIBN(0.1001).toNumber()).toBe(100);
-      expect(util.gweiDecToWEIBN(0.0109).toNumber()).toBe(11);
-      expect(util.gweiDecToWEIBN(0.0014).toNumber()).toBe(1);
-      expect(util.gweiDecToWEIBN(0.5676).toNumber()).toBe(568);
+      expect(util.gweiDecToWEIBN(0.1001).toNumber()).toBe(100100000);
+      expect(util.gweiDecToWEIBN(0.0109).toNumber()).toBe(10900000);
+      expect(util.gweiDecToWEIBN(0.0014).toNumber()).toBe(1400000);
+      expect(util.gweiDecToWEIBN(0.5676).toNumber()).toBe(567600000);
     });
 
     it('should handle NaN', () => {
diff --git a/src/util.ts b/src/util.ts
index 7f7149ab03a..fd7fc3f84a5 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -62,7 +62,7 @@ export function fractionBN(
   return targetBN.mul(numBN).div(denomBN);
 }
 
-const BN_1000 = new BN(1000, 10);
+const BN_1GWEI_IN_WEI = new BN(1000000000, 10);
 
 /**
  * Used to convert a base-10 number from GWEI to WEI. Can handle numbers with decimal parts
@@ -73,11 +73,11 @@ const BN_1000 = new BN(1000, 10);
 export function gweiDecToWEIBN(n: number | string) {
   const wholePart = Math.floor(Number(n));
   const decimalPartMatch = Number(n)
-    .toFixed(3)
+    .toFixed(9)
     .match(/\.(\d+)/u);
   const decimalPart = decimalPartMatch ? decimalPartMatch[1] : '0';
 
-  const wholePartAsWEI = new BN(wholePart, 10).mul(BN_1000);
+  const wholePartAsWEI = new BN(wholePart, 10).mul(BN_1GWEI_IN_WEI);
   const decimalPartAsWEI = new BN(decimalPart, 10);
 
   return wholePartAsWEI.add(decimalPartAsWEI);