diff --git a/configure.ac b/configure.ac
index fe5fa136..3e0bca31 100644
--- a/configure.ac
+++ b/configure.ac
@@ -14,6 +14,14 @@ AC_PREFIX_DEFAULT(/nix)
 
 AC_CANONICAL_HOST
 
+# Construct a Nix system name (like "i686-linux").
+AC_MSG_CHECKING([for the canonical Nix system name])
+machine_name=`uname -m`
+sys_name=`uname -s | tr [A-Z] [a-z]`
+system="${machine_name}-${sys_name}"
+AC_MSG_RESULT($system)
+AC_SUBST(system)
+
 AC_PROG_CC
 AC_PROG_CXX
 AC_PROG_RANLIB
diff --git a/scripts/nix-prefetch-url.in b/scripts/nix-prefetch-url.in
index 0873f5a8..05095568 100644
--- a/scripts/nix-prefetch-url.in
+++ b/scripts/nix-prefetch-url.in
@@ -25,7 +25,7 @@ rename $out, $out2;
 # Create a Nix expression.
 my $nixexpr =
     "(import @datadir@/nix/corepkgs/fetchurl) " .
-    "{url = $url; md5 = \"$hash\"; system = \"@host@\"}";
+    "{url = $url; md5 = \"$hash\"; system = \"@system@\"}";
 
 print "expr: $nixexpr\n";
 
diff --git a/scripts/nix-pull.in b/scripts/nix-pull.in
index 1453a46a..ded4281c 100644
--- a/scripts/nix-pull.in
+++ b/scripts/nix-pull.in
@@ -61,10 +61,10 @@ sub processURL {
                 # Nix archive from the network.
                 my $fetch =
                     "(import @datadir@/nix/corepkgs/fetchurl) " .
-                    "{url = $fullurl; md5 = \"$hash\"; system = \"@host@\"}";
+                    "{url = $fullurl; md5 = \"$hash\"; system = \"@system@\"}";
                 my $nixexpr =
                     "((import @datadir@/nix/corepkgs/nar/unnar.nix) " .
-                    "{narFile = ($fetch); outPath = \"$storepath\"; system = \"@host@\"}) ";
+                    "{narFile = ($fetch); outPath = \"$storepath\"; system = \"@system@\"}) ";
                 $fullexpr .= $nixexpr; # !!! O(n^2)?
 
                 push @srcpaths, $storepath;
diff --git a/scripts/nix-push.in b/scripts/nix-push.in
index c1624d83..38afc7f7 100644
--- a/scripts/nix-push.in
+++ b/scripts/nix-push.in
@@ -45,7 +45,7 @@ foreach my $id (@ARGV) {
         my $nixexpr = 
             "((import @datadir@/nix/corepkgs/nar/nar.nix) " .
             # !!! $path should be represented as a closure
-            "{path = \"$path\"; system = \"@host@\"}) ";
+            "{path = \"$path\"; system = \"@system@\"}) ";
         
         print NIX $nixexpr;
     }
diff --git a/src/libstore/Makefile.am b/src/libstore/Makefile.am
index 6605a76c..3e2777f6 100644
--- a/src/libstore/Makefile.am
+++ b/src/libstore/Makefile.am
@@ -6,5 +6,5 @@ libstore_a_SOURCES = \
  globals.cc globals.hh db.cc db.hh \
  references.cc references.hh pathlocks.cc pathlocks.hh
 
-AM_CXXFLAGS = -DSYSTEM=\"@host@\" -Wall \
+AM_CXXFLAGS = -Wall \
  -I.. -I../../externals/inst/include -I../libutil
diff --git a/src/libutil/Makefile.am b/src/libutil/Makefile.am
index 362a6e55..5d911186 100644
--- a/src/libutil/Makefile.am
+++ b/src/libutil/Makefile.am
@@ -3,7 +3,7 @@ noinst_LIBRARIES = libutil.a
 libutil_a_SOURCES = util.cc util.hh hash.cc hash.hh \
  archive.cc archive.hh md5.c md5.h aterm.cc aterm.hh
 
-AM_CXXFLAGS = -DSYSTEM=\"@host@\" -Wall -I.. -I../../externals/inst/include
+AM_CXXFLAGS = -DSYSTEM=\"@system@\" -Wall -I.. -I../../externals/inst/include
 
 check_PROGRAMS = test-aterm
 
diff --git a/substitute.mk b/substitute.mk
index 1f09f73b..6557e496 100644
--- a/substitute.mk
+++ b/substitute.mk
@@ -5,7 +5,7 @@
 	 -e "s^@sysconfdir\@^$(sysconfdir)^g" \
 	 -e "s^@localstatedir\@^$(localstatedir)^g" \
 	 -e "s^@datadir\@^$(datadir)^g" \
-	 -e "s^@host\@^$(host_triplet)^g" \
+	 -e "s^@system\@^$(system)^g" \
 	 -e "s^@wget\@^$(wget)^g" \
 	 < $< > $@ || rm $@
 	chmod +x $@