diff --git a/Makefile.rules b/Makefile.rules
index f3de568b23..07103a78df 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -724,6 +724,9 @@ GAP_KERNEL_MINOR_VERSION=$(GAP_KERNEL_MINOR_VERSION)
 GAP_BIN_DIR="$(abs_builddir)"
 GAP_LIB_DIR="$(abs_srcdir)"
 
+GAP="$(abs_builddir)/bin/gap.sh"
+GAC="$(abs_builddir)/gac"
+
 GAP_CC="$(CC)"
 GAP_CXX="$(CXX)"
 GAP_CFLAGS="$(GAP_CFLAGS)"
diff --git a/bin/BuildPackages.sh b/bin/BuildPackages.sh
index 7ae2b734e4..b1269bdcaa 100755
--- a/bin/BuildPackages.sh
+++ b/bin/BuildPackages.sh
@@ -48,8 +48,8 @@ while [[ "$#" -ge 1 ]]; do
     --with-gaproot=*) GAPROOT=${option#--with-gaproot=}; ;;
     --parallel)       PARALLEL=yes; ;;
 
-    --with-gap)       GAP="$1"; shift ;;
-    --with-gap=*)     GAP=${option#--with-gap=}; ;;
+    --with-gap)       GAP_EXE="$1"; shift ;;
+    --with-gap=*)     GAP_EXE=${option#--with-gap=}; ;;
 
     --no-color)       COLORS=no ;;
     --color)          COLORS=yes ;;
@@ -63,8 +63,6 @@ while [[ "$#" -ge 1 ]]; do
   esac
 done
 
-GAP="${GAP:-$GAPROOT/bin/gap.sh}"
-
 if [ "x$PARALLEL" = "xyes" ]; then
   export MAKEFLAGS="${MAKEFLAGS:--j3}"
 fi;
@@ -110,6 +108,20 @@ fi
 # read in sysinfo
 source "$GAPROOT/sysinfo.gap"
 
+# determine the GAP executable to call:
+# - if the user specified one explicitly via the `--gap` option, then
+#   GAP_EXE is set and we should use that
+# - otherwise if sysinfo.gap set the GAP variable, use that
+# - otherwise fall back to $GAPROOT/bin/gap.sh
+if [[ -n $GAP_EXE ]]
+then
+  GAP="$GAP_EXE"
+else
+  GAP="${GAP:-$GAPROOT/bin/gap.sh}"
+fi
+
+
+
 # detect whether GAP was built in 32bit mode
 # TODO: once all packages have adapted to the new build system,
 # this should no longer be necessary, as package build systems should
diff --git a/etc/Makefile.gappkg b/etc/Makefile.gappkg
index 30351af17a..e6c94e1fe6 100644
--- a/etc/Makefile.gappkg
+++ b/etc/Makefile.gappkg
@@ -50,9 +50,6 @@ endif
 KEXT_BINARCHDIR = bin/$(GAParch)
 KEXT_SO = $(KEXT_BINARCHDIR)/$(KEXT_NAME).so
 
-GAP = $(GAPPATH)/gap
-GAC = $(GAPPATH)/gac
-
 # override KEXT_RECONF if your package needs a different invocation
 # for reconfiguring (e.g. `./config.status --recheck` for autoconf)
 ifdef KEXT_USE_AUTOCONF