diff --git a/contracts/compound-rate-keeper/AbstractCompoundRateKeeper.sol b/contracts/compound-rate-keeper/AbstractCompoundRateKeeper.sol
index d2917d1d..ecd5a399 100644
--- a/contracts/compound-rate-keeper/AbstractCompoundRateKeeper.sol
+++ b/contracts/compound-rate-keeper/AbstractCompoundRateKeeper.sol
@@ -169,6 +169,37 @@ abstract contract AbstractCompoundRateKeeper is ICompoundRateKeeper, Initializab
         _changeCapitalizationPeriod(capitalizationPeriod_);
     }
 
+    /**
+     * @notice Implementation of exponentiation by squaring
+     * @param x_ basis, decimal number
+     * @param n_ power of x
+     * @param b_ precision of x
+     * @return z_ result
+     */
+    function _rpow(uint256 x_, uint256 n_, uint256 b_) internal pure returns (uint256 z_) {
+        if (x_ == 0) {
+            if (n_ == 0) {
+                z_ = b_;
+            } else {
+                z_ = 0;
+            }
+        } else {
+            if (n_ % 2 == 0) {
+                z_ = b_;
+            } else {
+                z_ = x_;
+            }
+            uint256 half = b_ / 2; // for rounding
+
+            for (uint256 i = n_ / 2; i >= 1; i = i / 2) {
+                x_ = (x_ * x_ + half) / b_;
+                if (i % 2 == 1) {
+                    z_ = (z_ * x_ + half) / b_;
+                }
+            }
+        }
+    }
+
     /**
      * @notice The private function to update the compound rate
      */
@@ -207,28 +238,4 @@ abstract contract AbstractCompoundRateKeeper is ICompoundRateKeeper, Initializab
     function _getMaxRate() private pure returns (uint256) {
         return type(uint128).max * PRECISION;
     }
-
-    function _rpow(uint256 x_, uint256 n_, uint256 b_) private pure returns (uint256 z_) {
-        if (x_ == 0) {
-            if (n_ == 0) {
-                z_ = b_;
-            } else {
-                z_ = 0;
-            }
-        } else {
-            if (n_ % 2 == 0) {
-                z_ = b_;
-            } else {
-                z_ = x_;
-            }
-            uint256 half = b_ / 2; // for rounding
-
-            for (uint256 i = n_ / 2; i >= 1; i = i / 2) {
-                x_ = (x_ * x_ + half) / b_;
-                if (i % 2 == 1) {
-                    z_ = (z_ * x_ + half) / b_;
-                }
-            }
-        }
-    }
 }
diff --git a/contracts/mock/compound-rate-keeper/CompoundRateKeeperMock.sol b/contracts/mock/compound-rate-keeper/CompoundRateKeeperMock.sol
index 391d6d01..575cb547 100644
--- a/contracts/mock/compound-rate-keeper/CompoundRateKeeperMock.sol
+++ b/contracts/mock/compound-rate-keeper/CompoundRateKeeperMock.sol
@@ -15,4 +15,8 @@ contract CompoundRateKeeperMock is OwnableCompoundRateKeeper {
         _setCapitalizationRate(capitalizationRate_);
         _setCapitalizationPeriod(capitalizationPeriod_);
     }
+
+    function rpow(uint256 x_, uint256 n_, uint256 b_) external pure returns (uint256 z_) {
+        return _rpow(x_, n_, b_);
+    }
 }
diff --git a/test/compound-rate-keeper/CompoundRateKeeper.test.ts b/test/compound-rate-keeper/CompoundRateKeeper.test.ts
index ab7cac68..e645b4a6 100644
--- a/test/compound-rate-keeper/CompoundRateKeeper.test.ts
+++ b/test/compound-rate-keeper/CompoundRateKeeper.test.ts
@@ -261,5 +261,10 @@ describe("CompoundRateKeeper", () => {
     it("check max timestamp for 1000%", async () => {
       await checkByParams(11);
     });
+
+    it("check correct work of rpow function", async () => {
+      expect(await keeper.rpow(0, 0, 5)).to.equal(5);
+      expect(await keeper.rpow(0, 1, 5)).to.equal(0);
+    });
   });
 });