diff --git a/src/libstore/build.hh b/src/libstore/build.hh
index 2c6bcf9f2d..45997ebb24 100644
--- a/src/libstore/build.hh
+++ b/src/libstore/build.hh
@@ -28,4 +28,9 @@ Derivation derivationFromPath(const Path & drvPath);
 void computeFSClosure(const Path & storePath,
     PathSet & paths, bool flipDirection = false);
 
+/* Return the path corresponding to the output identifier `id' in the
+   given derivation. */
+Path findOutput(const Derivation & drv, string id);
+    
+
 #endif /* !__BUILD_H */
diff --git a/src/libstore/misc.cc b/src/libstore/misc.cc
index 5f20ee2775..f3cc98bf4e 100644
--- a/src/libstore/misc.cc
+++ b/src/libstore/misc.cc
@@ -27,3 +27,12 @@ void computeFSClosure(const Path & storePath,
          i != references.end(); ++i)
         computeFSClosure(*i, paths, flipDirection);
 }
+
+
+ Path findOutput(const Derivation & drv, string id)
+{
+    for (DerivationOutputs::const_iterator i = drv.outputs.begin();
+         i != drv.outputs.end(); ++i)
+        if (i->first == id) return i->second.path;
+    throw Error(format("derivation has no output `%1%'") % id);
+}
diff --git a/src/nix-env/main.cc b/src/nix-env/main.cc
index a250413ab1..bab1f7fe14 100644
--- a/src/nix-env/main.cc
+++ b/src/nix-env/main.cc
@@ -2,6 +2,7 @@
 #include "names.hh"
 #include "globals.hh"
 #include "build.hh"
+#include "gc.hh"
 #include "shared.hh"
 #include "parser.hh"
 #include "eval.hh"
@@ -226,6 +227,12 @@ static void createUserEnv(EvalState & state, const UserEnvElems & elems,
             ));
         manifest = ATinsert(manifest, t);
         inputs = ATinsert(inputs, makeStr(toATerm(i->second.outPath)));
+
+        /* This is only necessary when installing store paths, e.g.,
+           `nix-env -i /nix/store/abcd...-foo'. */
+        addTempRoot(i->second.outPath);
+        ensurePath(i->second.outPath);
+        
         references.insert(i->second.outPath);
         if (drvPath != "") references.insert(drvPath);
     }
@@ -270,7 +277,11 @@ static void queryInstSources(EvalState & state,
     const InstallSourceInfo & instSource, const Strings & args,
     UserEnvElems & elems)
 {
-    switch (instSource.type) {
+    InstallSourceType type = instSource.type;
+    if (type == srcUnknown && args.size() > 0 && args.front()[0] == '/')
+        type = srcStorePaths;
+    
+    switch (type) {
 
         /* Get the available user environment elements from the
            derivations specified in a Nix expression, including only
@@ -333,6 +344,32 @@ static void queryInstSources(EvalState & state,
             break;
 
         case srcStorePaths:
+
+            for (Strings::const_iterator i = args.begin();
+                 i != args.end(); ++i)
+            {
+                assertStorePath(*i);
+
+                UserEnvElem elem;
+                string name = baseNameOf(*i);
+                unsigned int dash = name.find('-');
+                if (dash != string::npos)
+                    name = string(name, dash + 1);
+
+                if (isDerivation(*i)) {
+                    elem.drvPath = *i;
+                    elem.outPath = findOutput(derivationFromPath(*i), "out");
+                    if (name.size() >= drvExtension.size() &&
+                        string(name, name.size() - drvExtension.size()) == drvExtension)
+                        name = string(name, 0, name.size() - drvExtension.size());
+                }
+                else elem.outPath = *i;
+
+                elem.name = name;
+
+                elems[elem.outPath] = elem;
+            }
+            
             break;
 
         case srcProfile:
diff --git a/src/nix-store/main.cc b/src/nix-store/main.cc
index fa7960c382..a93956ab7a 100644
--- a/src/nix-store/main.cc
+++ b/src/nix-store/main.cc
@@ -23,15 +23,6 @@ static int rootNr = 0;
 static bool indirectRoot = false;
 
 
-static Path findOutput(const Derivation & drv, string id)
-{
-    for (DerivationOutputs::const_iterator i = drv.outputs.begin();
-         i != drv.outputs.end(); ++i)
-        if (i->first == id) return i->second.path;
-    throw Error(format("derivation has no output `%1%'") % id);
-}
-
-
 static Path fixPath(Path path)
 {
     path = absPath(path);