diff --git a/perl/lib/Nix/Store.xs b/perl/lib/Nix/Store.xs
index af71ad955..9e51ea337 100644
--- a/perl/lib/Nix/Store.xs
+++ b/perl/lib/Nix/Store.xs
@@ -18,10 +18,8 @@ using namespace nix;
 void doInit() 
 {
     if (!store) {
-        nixStore = canonPath(getEnv("NIX_STORE_DIR", getEnv("NIX_STORE", "/nix/store")));
-        nixStateDir = canonPath(getEnv("NIX_STATE_DIR", "/nix/var/nix"));
-        nixDBPath = getEnv("NIX_DB_DIR", nixStateDir + "/db");
         try {
+            setDefaultsFromEnvironment();
             store = openStore();
         } catch (Error & e) {
             croak(e.what());
diff --git a/src/libmain/Makefile.am b/src/libmain/Makefile.am
index ababc3595..404353c62 100644
--- a/src/libmain/Makefile.am
+++ b/src/libmain/Makefile.am
@@ -7,13 +7,6 @@ libmain_la_LIBADD = ../libstore/libstore.la @BDW_GC_LIBS@
 pkginclude_HEADERS = shared.hh
 
 AM_CXXFLAGS = \
- -DNIX_STORE_DIR=\"$(storedir)\" \
- -DNIX_DATA_DIR=\"$(datadir)\" \
- -DNIX_STATE_DIR=\"$(localstatedir)/nix\" \
- -DNIX_LOG_DIR=\"$(localstatedir)/log/nix\" \
- -DNIX_CONF_DIR=\"$(sysconfdir)/nix\" \
- -DNIX_LIBEXEC_DIR=\"$(libexecdir)\" \
- -DNIX_BIN_DIR=\"$(bindir)\" \
  -DNIX_VERSION=\"$(VERSION)\" \
  -I$(srcdir)/.. -I$(srcdir)/../libutil \
  -I$(srcdir)/../libstore
diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc
index 8532cdaad..f7c11ed05 100644
--- a/src/libmain/shared.cc
+++ b/src/libmain/shared.cc
@@ -120,30 +120,8 @@ static bool showTrace = false;
    processor. */
 static void initAndRun(int argc, char * * argv)
 {
-    /* Setup Nix paths. */
-    nixStore = canonPath(getEnv("NIX_STORE_DIR", getEnv("NIX_STORE", NIX_STORE_DIR)));
-    nixDataDir = canonPath(getEnv("NIX_DATA_DIR", NIX_DATA_DIR));
-    nixLogDir = canonPath(getEnv("NIX_LOG_DIR", NIX_LOG_DIR));
-    nixStateDir = canonPath(getEnv("NIX_STATE_DIR", NIX_STATE_DIR));
-    nixDBPath = getEnv("NIX_DB_DIR", nixStateDir + "/db");
-    nixConfDir = canonPath(getEnv("NIX_CONF_DIR", NIX_CONF_DIR));
-    nixLibexecDir = canonPath(getEnv("NIX_LIBEXEC_DIR", NIX_LIBEXEC_DIR));
-    nixBinDir = canonPath(getEnv("NIX_BIN_DIR", NIX_BIN_DIR));
-
-    string subs = getEnv("NIX_SUBSTITUTERS", "default");
-    if (subs == "default") {
-        substituters.push_back(nixLibexecDir + "/nix/substituters/copy-from-other-stores.pl");
-        substituters.push_back(nixLibexecDir + "/nix/substituters/download-using-manifests.pl");
-    } else
-        substituters = tokenizeString(subs, ":");
-
-    /* Get some settings from the configuration file. */
-    thisSystem = querySetting("system", SYSTEM);
-    maxBuildJobs = queryIntSetting("build-max-jobs", 1);
-    buildCores = queryIntSetting("build-cores", 1);
-    maxSilentTime = queryIntSetting("build-max-silent-time", 0);
-    buildTimeout = queryIntSetting("build-timeout", 0);
-
+    setDefaultsFromEnvironment();
+    
     /* Catch SIGINT. */
     struct sigaction act;
     act.sa_handler = sigintHandler;
diff --git a/src/libstore/Makefile.am b/src/libstore/Makefile.am
index e19256b92..39a61233b 100644
--- a/src/libstore/Makefile.am
+++ b/src/libstore/Makefile.am
@@ -15,7 +15,16 @@ libstore_la_LIBADD = ../libutil/libutil.la ../boost/format/libformat.la ${aterm_
 EXTRA_DIST = schema.sql
 
 AM_CXXFLAGS = -Wall \
- ${sqlite_include} -I$(srcdir)/.. -I$(srcdir)/../libutil
+ ${sqlite_include} -I$(srcdir)/.. -I$(srcdir)/../libutil \
+ -DNIX_STORE_DIR=\"$(storedir)\" \
+ -DNIX_DATA_DIR=\"$(datadir)\" \
+ -DNIX_STATE_DIR=\"$(localstatedir)/nix\" \
+ -DNIX_LOG_DIR=\"$(localstatedir)/log/nix\" \
+ -DNIX_CONF_DIR=\"$(sysconfdir)/nix\" \
+ -DNIX_LIBEXEC_DIR=\"$(libexecdir)\" \
+ -DNIX_BIN_DIR=\"$(bindir)\" \
+ -I$(srcdir)/.. -I$(srcdir)/../libutil \
+ -I$(srcdir)/../libstore
 
 local-store.lo: schema.sql.hh
 
diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc
index 2e9dc8823..5c22f1406 100644
--- a/src/libstore/globals.cc
+++ b/src/libstore/globals.cc
@@ -1,3 +1,5 @@
+#include "config.h"
+
 #include "globals.hh"
 #include "util.hh"
 
@@ -138,5 +140,33 @@ void reloadSettings()
     settings.clear();
 }
 
+
+void setDefaultsFromEnvironment()
+{
+    /* Setup Nix paths. */
+    nixStore = canonPath(getEnv("NIX_STORE_DIR", getEnv("NIX_STORE", NIX_STORE_DIR)));
+    nixDataDir = canonPath(getEnv("NIX_DATA_DIR", NIX_DATA_DIR));
+    nixLogDir = canonPath(getEnv("NIX_LOG_DIR", NIX_LOG_DIR));
+    nixStateDir = canonPath(getEnv("NIX_STATE_DIR", NIX_STATE_DIR));
+    nixDBPath = getEnv("NIX_DB_DIR", nixStateDir + "/db");
+    nixConfDir = canonPath(getEnv("NIX_CONF_DIR", NIX_CONF_DIR));
+    nixLibexecDir = canonPath(getEnv("NIX_LIBEXEC_DIR", NIX_LIBEXEC_DIR));
+    nixBinDir = canonPath(getEnv("NIX_BIN_DIR", NIX_BIN_DIR));
+
+    string subs = getEnv("NIX_SUBSTITUTERS", "default");
+    if (subs == "default") {
+        substituters.push_back(nixLibexecDir + "/nix/substituters/copy-from-other-stores.pl");
+        substituters.push_back(nixLibexecDir + "/nix/substituters/download-using-manifests.pl");
+    } else
+        substituters = tokenizeString(subs, ":");
+
+    /* Get some settings from the configuration file. */
+    thisSystem = querySetting("system", SYSTEM);
+    maxBuildJobs = queryIntSetting("build-max-jobs", 1);
+    buildCores = queryIntSetting("build-cores", 1);
+    maxSilentTime = queryIntSetting("build-max-silent-time", 0);
+    buildTimeout = queryIntSetting("build-timeout", 0);
+}
+
  
 }
diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh
index 231c1f850..12a9b9ca1 100644
--- a/src/libstore/globals.hh
+++ b/src/libstore/globals.hh
@@ -114,7 +114,9 @@ void overrideSetting(const string & name, const Strings & value);
 
 void reloadSettings();
 
-    
+void setDefaultsFromEnvironment();
+
+
 }