diff --git a/include/primesieve/nthPrimeApprox.hpp b/include/primesieve/nthPrimeApprox.hpp
index 58e68891c..94d27e132 100644
--- a/include/primesieve/nthPrimeApprox.hpp
+++ b/include/primesieve/nthPrimeApprox.hpp
@@ -17,7 +17,7 @@ uint64_t Li(uint64_t x);
 uint64_t Li_inverse(uint64_t x);
 uint64_t Ri(uint64_t x);
 uint64_t Ri_inverse(uint64_t x);
-uint64_t primesApprox(uint64_t x);
+uint64_t primePiApprox(uint64_t x);
 uint64_t nthPrimeApprox(uint64_t n);
 
 } // namespace
diff --git a/src/nthPrime.cpp b/src/nthPrime.cpp
index e524220dc..d274e25e3 100644
--- a/src/nthPrime.cpp
+++ b/src/nthPrime.cpp
@@ -60,7 +60,7 @@ uint64_t PrimeSieve::nthPrime(int64_t n, uint64_t start)
 
   setStart(start);
   auto t1 = std::chrono::system_clock::now();
-  uint64_t nApprox = checkedAdd(primesApprox(start), n);
+  uint64_t nApprox = checkedAdd(primePiApprox(start), n);
   nApprox = std::min(nApprox, max_n);
   uint64_t primeApprox = nthPrimeApprox(nApprox);
   primeApprox = std::max(primeApprox, start);
@@ -125,7 +125,7 @@ uint64_t PrimeSieve::negativeNthPrime(int64_t n, uint64_t start)
 
   setStart(start);
   auto t1 = std::chrono::system_clock::now();
-  uint64_t nApprox = checkedSub(primesApprox(start), n);
+  uint64_t nApprox = checkedSub(primePiApprox(start), n);
   nApprox = std::min(nApprox, max_n);
   uint64_t primeApprox = nthPrimeApprox(nApprox);
   primeApprox = std::min(primeApprox, start);
diff --git a/src/nthPrimeApprox.cpp b/src/nthPrimeApprox.cpp
index b55f214b3..4c9e573ff 100644
--- a/src/nthPrimeApprox.cpp
+++ b/src/nthPrimeApprox.cpp
@@ -254,7 +254,7 @@ uint64_t Ri_inverse(uint64_t x)
   return (uint64_t) ::Ri_inverse((long double) x);
 }
 
-uint64_t primesApprox(uint64_t x)
+uint64_t primePiApprox(uint64_t x)
 {
   // Li(x) is faster but less accurate than Ri(x).
   // For small n speed is more important than accuracy.