diff --git a/doc/sf/igamma.qbk b/doc/sf/igamma.qbk
index 57e520513..1ce33d7a7 100644
--- a/doc/sf/igamma.qbk
+++ b/doc/sf/igamma.qbk
@@ -79,10 +79,10 @@ This function changes rapidly from 0 to 1 around the point z == a:
 [graph gamma_p]
 
    template <class T1, class T2>
-   BOOST_MATH_GPU_ENABLED ``__sf_result`` lgamma_q(T1 a, T2 z);
+   BOOST_MATH_GPU_ENABLED ``__sf_result`` lgamma_p(T1 a, T2 z);
    
    template <class T1, class T2, class ``__Policy``>
-   BOOST_MATH_GPU_ENABLED ``__sf_result`` lgamma_q(T1 a, T2 z, const ``__Policy``&);
+   BOOST_MATH_GPU_ENABLED ``__sf_result`` lgamma_p(T1 a, T2 z, const ``__Policy``&);
 
 Returns the natural log of the normalized lower incomplete gamma function 
 of a and z.  
diff --git a/include/boost/math/special_functions/gamma.hpp b/include/boost/math/special_functions/gamma.hpp
index e67752861..a9c17da88 100644
--- a/include/boost/math/special_functions/gamma.hpp
+++ b/include/boost/math/special_functions/gamma.hpp
@@ -1842,9 +1842,7 @@ BOOST_MATH_GPU_ENABLED T lgamma_incomplete_lower_imp(T a, T x, const Policy& pol
    // we will lose precision in the result, selection logic here is extracted from gamma_incomplete_imp_final:
    //
    bool need_p = false;
-   if ((x < 0.5) && (T(-0.4) / log(x) < a))
-      need_p = true;
-   else if ((x < 1.1) && (x >= 0.5) && (x * 0.75f < a))
+   if ((x < 1.1) && (x >= 0.5) && (x * 0.75f < a))
       need_p = true;
    else if ((x < a) && (x >= 1.1))
       need_p = true;