diff --git a/CMakeLists.txt b/CMakeLists.txt
index 41ca8d8ee..4edc89ebc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -417,7 +417,7 @@ set(LIBOPENMC_FORTRAN_SRC
 )
 set(LIBOPENMC_CXX_SRC
   src/random_lcg.h
-  src/random_lcg.C)
+  src/random_lcg.cpp)
 add_library(libopenmc SHARED ${LIBOPENMC_FORTRAN_SRC} ${LIBOPENMC_CXX_SRC})
 set_target_properties(libopenmc PROPERTIES OUTPUT_NAME openmc)
 add_executable(${program} src/main.F90)
diff --git a/src/random_lcg.C b/src/random_lcg.cpp
similarity index 95%
rename from src/random_lcg.C
rename to src/random_lcg.cpp
index ea79be67f..047bda8e5 100644
--- a/src/random_lcg.C
+++ b/src/random_lcg.cpp
@@ -21,7 +21,7 @@ constexpr uint64_t prn_mod    {0x8000000000000000};      // 2^63
 constexpr uint64_t prn_mask   {0x7fffffffffffffff};      // 2^63 - 1
 constexpr uint64_t prn_stride {152917LL};                // stride between
                                                          //   particles
-constexpr double   prn_norm   {pow(2, -63)};             // 2^-63
+constexpr double   prn_norm   {1.0 / prn_mod};           // 2^-63
 
 // Current PRNG state
 uint64_t prn_seed[N_STREAMS];  // current seed
@@ -135,10 +135,11 @@ openmc_set_seed(int64_t new_seed)
 {
   seed = new_seed;
 #pragma omp parallel
-  for (int i = 0; i < N_STREAMS; i++) {
-    prn_seed[i] = seed + i;
+  {
+    for (int i = 0; i < N_STREAMS; i++) {
+      prn_seed[i] = seed + i;
+    }
+    prn_set_stream(STREAM_TRACKING);
   }
-  prn_set_stream(STREAM_TRACKING);
-#pragma end omp parallel
   return 0;
 }