diff --git a/src/sage/config.py.in b/src/sage/config.py.in
index de5ad8b2169..4efc3ca4ce0 100644
--- a/src/sage/config.py.in
+++ b/src/sage/config.py.in
@@ -13,10 +13,10 @@ SAGE_LOCAL = "@prefix@"
 # The semicolon-separated list of GAP root paths. This is the list of
 # locations that are searched for GAP packages. This is passed directly
 # to GAP via the -l flag.
-GAP_ROOT_PATHS = "@GAP_ROOT_PATHS@".replace("${prefix}", SAGE_LOCAL)
+GAP_ROOT_PATHS = "@GENTOO_PORTAGE_EPREFIX@/usr/@libdir@/gap;@GENTOO_PORTAGE_EPREFIX@/usr/share/gap"
 
 # The path to the standalone maxima executable.
-MAXIMA = "@SAGE_MAXIMA@".replace("${prefix}", SAGE_LOCAL)
+MAXIMA = "maxima -l ecl"
 
 # Set this to the empty string if your ECL can load maxima without
 # further prodding.
@@ -38,15 +38,15 @@ SAGE_NAUTY_BINS_PREFIX = "@SAGE_NAUTY_BINS_PREFIX@"
 SAGE_ECMBIN = "@SAGE_ECMBIN@"
 
 # Names or paths of the 4ti2 executables
-FOURTITWO_HILBERT = "@FOURTITWO_HILBERT@"
-FOURTITWO_MARKOV = "@FOURTITWO_MARKOV@"
-FOURTITWO_GRAVER = "@FOURTITWO_GRAVER@"
-FOURTITWO_ZSOLVE = "@FOURTITWO_ZSOLVE@"
-FOURTITWO_QSOLVE = "@FOURTITWO_QSOLVE@"
-FOURTITWO_RAYS = "@FOURTITWO_RAYS@"
-FOURTITWO_PPI = "@FOURTITWO_PPI@"
-FOURTITWO_CIRCUITS = "@FOURTITWO_CIRCUITS@"
-FOURTITWO_GROEBNER = "@FOURTITWO_GROEBNER@"
+FOURTITWO_HILBERT = "hilbert"
+FOURTITWO_MARKOV = "markov"
+FOURTITWO_GRAVER = "graver"
+FOURTITWO_ZSOLVE = "zsolve"
+FOURTITWO_QSOLVE = "qsolve"
+FOURTITWO_RAYS = "rays"
+FOURTITWO_PPI = "ppi"
+FOURTITWO_CIRCUITS = "circuits"
+FOURTITWO_GROEBNER = "groebner"
 
 # Colon-separated list of pkg-config modules to search for cblas functionality.
 # We hard-code it here as cblas because configure (build/pkgs/openblas/spkg-configure.m4)
@@ -58,13 +58,23 @@ SAGE_ARCHFLAGS = "@SAGE_ARCHFLAGS@"
 SAGE_PKG_CONFIG_PATH = "@SAGE_PKG_CONFIG_PATH@".replace("$SAGE_LOCAL", SAGE_LOCAL)
 
 # Used in sage.repl.ipython_kernel.install
-MATHJAX_DIR = "@SAGE_MATHJAX_DIR@".replace("${prefix}", SAGE_LOCAL)
+MATHJAX_DIR = "@GENTOO_PORTAGE_EPREFIX@/usr/share/mathjax"
 THREEJS_DIR = SAGE_LOCAL + "/share/threejs-sage"
 
 # OpenMP flags, if available.
 OPENMP_CFLAGS = "@OPENMP_CFLAGS@"
 OPENMP_CXXFLAGS = "@OPENMP_CXXFLAGS@"
 
+# Some Gentoo definitions
+SAGE_SHARE   = "@GENTOO_PORTAGE_EPREFIX@/usr/share/sage"
+SAGE_DOC     = "@GENTOO_PORTAGE_EPREFIX@/usr/share/doc/@GENTOO_PORTAGE_PF@"
+
+JMOL_DIR     = "@GENTOO_PORTAGE_EPREFIX@/usr/share/sage-jmol-bin/lib"
+MTXLIB       = "@GENTOO_PORTAGE_EPREFIX@/usr/share/meataxe"
+PPLPY_DOCS   = "@GENTOO_PORTAGE_EPREFIX@/usr/share/doc/@PPLY_DOC_VERS@/html"
+
+LIE_INFO_DIR = "@GENTOO_PORTAGE_EPREFIX@/usr/share/lie"
+
 
 def is_editable_install() -> bool:
     """