diff --git a/packages/stargate/src/fee.spec.ts b/packages/stargate/src/fee.spec.ts
index c2457a2c36..ec0839f367 100644
--- a/packages/stargate/src/fee.spec.ts
+++ b/packages/stargate/src/fee.spec.ts
@@ -51,16 +51,16 @@ describe("GasPrice", () => {
       expect(() => GasPrice.fromString("234")).toThrowError(/Invalid gas price string/i);
       expect(() => GasPrice.fromString("-234tkn")).toThrowError(/Invalid gas price string/i);
       // Checks details of <denom>
-      expect(() => GasPrice.fromString("234t")).toThrowError(/Invalid gas price string/i);
-      expect(() => GasPrice.fromString("234tt")).toThrowError(/Invalid gas price string/i);
+      expect(() => GasPrice.fromString("234t")).toThrowError(/denom must be between 3 and 128 characters/i);
+      expect(() => GasPrice.fromString("234tt")).toThrowError(/denom must be between 3 and 128 characters/i);
       expect(() =>
         GasPrice.fromString(
           "234ttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt",
         ),
-      ).toThrowError(/Invalid gas price string/i);
+      ).toThrowError(/denom must be between 3 and 128 characters/i);
       // Checks details of <amount>
-      expect(() => GasPrice.fromString("3.utkn")).toThrowError(/Invalid gas price string/i);
-      expect(() => GasPrice.fromString("..utkn")).toThrowError(/Invalid gas price string/i);
+      expect(() => GasPrice.fromString("3.utkn")).toThrowError(/Fractional part missing/i);
+      expect(() => GasPrice.fromString("..utkn")).toThrowError(/More than one separator found/i);
     });
   });
 
diff --git a/packages/stargate/src/fee.ts b/packages/stargate/src/fee.ts
index a1332dd9c8..9ca8682a44 100644
--- a/packages/stargate/src/fee.ts
+++ b/packages/stargate/src/fee.ts
@@ -2,6 +2,18 @@ import { StdFee } from "@cosmjs/amino";
 import { Decimal, Uint53 } from "@cosmjs/math";
 import { coins } from "@cosmjs/proto-signing";
 
+/**
+ * Denom checker for the Cosmos SDK 0.42 denom pattern
+ * (https://github.com/cosmos/cosmos-sdk/blob/v0.42.4/types/coin.go#L599-L601).
+ *
+ * This is like a regexp but with helpful error messages.
+ */
+function checkDenom(denom: string): void {
+  if (denom.length < 3 || denom.length > 128) {
+    throw new Error("Denom must be between 3 and 128 characters");
+  }
+}
+
 /**
  * A gas price, i.e. the price of a single unit of gas. This is typically a fraction of
  * the smallest fee token unit, such as 0.012utoken.
@@ -25,11 +37,12 @@ export class GasPrice {
    */
   public static fromString(gasPrice: string): GasPrice {
     // Use Decimal.fromUserInput and checkDenom for detailed checks and helpful error messages
-    const matchResult = gasPrice.match(/^(\d+(?:\.\d+)?|\.\d+)([a-zA-Z][a-zA-Z0-9/:._-]{2,127})$/i);
+    const matchResult = gasPrice.match(/^([0-9.]+)([a-zA-Z][a-zA-Z0-9/:._-]*)$/i);
     if (!matchResult) {
       throw new Error("Invalid gas price string");
     }
     const [_, amount, denom] = matchResult;
+    checkDenom(denom);
     const fractionalDigits = 18;
     const decimalAmount = Decimal.fromUserInput(amount, fractionalDigits);
     return new GasPrice(decimalAmount, denom);