diff --git a/test/test_normal.cpp b/test/test_normal.cpp
index c03090439..a4012e071 100644
--- a/test/test_normal.cpp
+++ b/test/test_normal.cpp
@@ -81,7 +81,7 @@ template <class RealType>
 void test_spots(RealType)
 {
    // Basic sanity checks
-   RealType tolerance = static_cast<RealType>(std::pow(10., -(4-2))); // 1e-4 (as %)
+   RealType tolerance = 1e-2f; // 1e-4 (as %)
    // Some tests only pass at 1e-4 because values generated by
    // http://faculty.vassar.edu/lowry/VassarStats.html
    // give only 5 or 6 *fixed* places, so small values have fewer digits.
diff --git a/test/test_poisson.cpp b/test/test_poisson.cpp
index 7773d4a19..361637cd7 100644
--- a/test/test_poisson.cpp
+++ b/test/test_poisson.cpp
@@ -63,7 +63,7 @@ void test_spots(RealType)
   }
 
    decdigits -= 1; // Perhaps allow some decimal digit(s) margin of numerical error.
-   RealType tolerance = static_cast<RealType>(std::pow(10., -(decdigits-2))); // 1e-6 (-2 so as %)
+   RealType tolerance = static_cast<RealType>(std::pow(10., static_cast<double>(2-decdigits))); // 1e-6 (-2 so as %)
    tolerance *= 2; // Allow some bit(s) small margin (2 means + or - 1 bit) of numerical error.
    // Typically 2e-13% = 2e-15 as fraction for double.
 
diff --git a/test/test_students_t.cpp b/test/test_students_t.cpp
index 9d2af265e..153f360c7 100644
--- a/test/test_students_t.cpp
+++ b/test/test_students_t.cpp
@@ -54,7 +54,7 @@ template <class RealType>
 void test_spots(RealType)
 {
   // Basic sanity checks
-   RealType tolerance = static_cast<RealType>(std::pow(10., -(6-2))); // 1e-6 (as %)
+   RealType tolerance = 1e-4; // 1e-6 (as %)
    // Some tests only pass at 1e-5 because probability value is less accurate,
    // a digit in 6th decimal place, although calculated using
    // a t-distribution generator (claimed 6 decimal digits) at