diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc
index a94e60aca..635ce19b6 100644
--- a/src/libcmd/installables.cc
+++ b/src/libcmd/installables.cc
@@ -621,11 +621,15 @@ std::tuple<std::string, FlakeRef, InstallableValue::DerivationInfo> InstallableF
     auto drvPath = attr->forceDerivation();
 
     std::set<std::string> outputsToInstall;
+    std::optional<NixInt> priority;
 
-    if (auto aMeta = attr->maybeGetAttr(state->sMeta))
+    if (auto aMeta = attr->maybeGetAttr(state->sMeta)) {
         if (auto aOutputsToInstall = aMeta->maybeGetAttr("outputsToInstall"))
             for (auto & s : aOutputsToInstall->getListOfStrings())
                 outputsToInstall.insert(s);
+        if (auto aPriority = aMeta->maybeGetAttr("priority"))
+            priority = aPriority->getInt();
+    }
 
     if (outputsToInstall.empty() || std::get_if<AllOutputs>(&outputsSpec)) {
         outputsToInstall.clear();
@@ -643,6 +647,7 @@ std::tuple<std::string, FlakeRef, InstallableValue::DerivationInfo> InstallableF
     auto drvInfo = DerivationInfo {
         .drvPath = std::move(drvPath),
         .outputsToInstall = std::move(outputsToInstall),
+        .priority = priority,
     };
 
     return {attrPath, getLockedFlake()->flake.lockedRef, std::move(drvInfo)};
diff --git a/src/libcmd/installables.hh b/src/libcmd/installables.hh
index 1a5a96153..5d715210e 100644
--- a/src/libcmd/installables.hh
+++ b/src/libcmd/installables.hh
@@ -142,6 +142,7 @@ struct InstallableValue : Installable
     {
         StorePath drvPath;
         std::set<std::string> outputsToInstall;
+        std::optional<NixInt> priority;
     };
 
     virtual std::vector<DerivationInfo> toDerivations() = 0;
diff --git a/src/libexpr/eval-cache.cc b/src/libexpr/eval-cache.cc
index 0eb4bc79e..6a2e775d0 100644
--- a/src/libexpr/eval-cache.cc
+++ b/src/libexpr/eval-cache.cc
@@ -47,7 +47,7 @@ struct AttrDb
     {
         auto state(_state->lock());
 
-        Path cacheDir = getCacheDir() + "/nix/eval-cache-v3";
+        Path cacheDir = getCacheDir() + "/nix/eval-cache-v4";
         createDirs(cacheDir);
 
         Path dbPath = cacheDir + "/" + fingerprint.to_string(Base16, false) + ".sqlite";
@@ -175,6 +175,24 @@ struct AttrDb
         });
     }
 
+    AttrId setInt(
+        AttrKey key,
+        int n)
+    {
+        return doSQLite([&]()
+        {
+            auto state(_state->lock());
+
+            state->insertAttribute.use()
+                (key.first)
+                (symbols[key.second])
+                (AttrType::Int)
+                (n).exec();
+
+            return state->db.getLastInsertedRowId();
+        });
+    }
+
     AttrId setListOfStrings(
         AttrKey key,
         const std::vector<std::string> & l)
@@ -287,6 +305,8 @@ struct AttrDb
             }
             case AttrType::Bool:
                 return {{rowId, queryAttribute.getInt(2) != 0}};
+            case AttrType::Int:
+                return {{rowId, int_t{queryAttribute.getInt(2)}}};
             case AttrType::ListOfStrings:
                 return {{rowId, tokenizeString<std::vector<std::string>>(queryAttribute.getStr(2), "\t")}};
             case AttrType::Missing:
@@ -426,6 +446,8 @@ Value & AttrCursor::forceValue()
             cachedValue = {root->db->setString(getKey(), v.path), string_t{v.path, {}}};
         else if (v.type() == nBool)
             cachedValue = {root->db->setBool(getKey(), v.boolean), v.boolean};
+        else if (v.type() == nInt)
+            cachedValue = {root->db->setInt(getKey(), v.integer), int_t{v.integer}};
         else if (v.type() == nAttrs)
             ; // FIXME: do something?
         else
@@ -621,6 +643,28 @@ bool AttrCursor::getBool()
     return v.boolean;
 }
 
+NixInt AttrCursor::getInt()
+{
+    if (root->db) {
+        if (!cachedValue)
+            cachedValue = root->db->getAttr(getKey());
+        if (cachedValue && !std::get_if<placeholder_t>(&cachedValue->second)) {
+            if (auto i = std::get_if<int_t>(&cachedValue->second)) {
+                debug("using cached Integer attribute '%s'", getAttrPathStr());
+                return i->x;
+            } else
+                throw TypeError("'%s' is not an Integer", getAttrPathStr());
+        }
+    }
+
+    auto & v = forceValue();
+
+    if (v.type() != nInt)
+        throw TypeError("'%s' is not an Integer", getAttrPathStr());
+
+    return v.integer;
+}
+
 std::vector<std::string> AttrCursor::getListOfStrings()
 {
     if (root->db) {
diff --git a/src/libexpr/eval-cache.hh b/src/libexpr/eval-cache.hh
index 636e293ad..c93e55b93 100644
--- a/src/libexpr/eval-cache.hh
+++ b/src/libexpr/eval-cache.hh
@@ -45,12 +45,14 @@ enum AttrType {
     Failed = 5,
     Bool = 6,
     ListOfStrings = 7,
+    Int = 8,
 };
 
 struct placeholder_t {};
 struct missing_t {};
 struct misc_t {};
 struct failed_t {};
+struct int_t { NixInt x; };
 typedef uint64_t AttrId;
 typedef std::pair<AttrId, Symbol> AttrKey;
 typedef std::pair<std::string, NixStringContext> string_t;
@@ -63,6 +65,7 @@ typedef std::variant<
     misc_t,
     failed_t,
     bool,
+    int_t,
     std::vector<std::string>
     > AttrValue;
 
@@ -116,6 +119,8 @@ public:
 
     bool getBool();
 
+    NixInt getInt();
+
     std::vector<std::string> getListOfStrings();
 
     std::vector<Symbol> getAttrs();
diff --git a/src/libstore/builtins/buildenv.cc b/src/libstore/builtins/buildenv.cc
index 6f6ad57cb..47458a388 100644
--- a/src/libstore/builtins/buildenv.cc
+++ b/src/libstore/builtins/buildenv.cc
@@ -93,8 +93,9 @@ static void createLinks(State & state, const Path & srcDir, const Path & dstDir,
                     auto prevPriority = state.priorities[dstFile];
                     if (prevPriority == priority)
                         throw Error(
-                                "packages '%1%' and '%2%' have the same priority %3%; "
+                                "files '%1%' and '%2%' have the same priority %3%; "
                                 "use 'nix-env --set-flag priority NUMBER INSTALLED_PKGNAME' "
+                                "or type 'nix profile install --help' if using 'nix profile' to find out how"
                                 "to change the priority of one of the conflicting packages"
                                 " (0 being the highest priority)",
                                 srcFile, readLink(dstFile), priority);
diff --git a/src/nix/profile.cc b/src/nix/profile.cc
index 685776bec..1aae347df 100644
--- a/src/nix/profile.cc
+++ b/src/nix/profile.cc
@@ -37,7 +37,7 @@ struct ProfileElement
     StorePathSet storePaths;
     std::optional<ProfileElementSource> source;
     bool active = true;
-    // FIXME: priority
+    int priority = 5;
 
     std::string describe() const
     {
@@ -116,6 +116,9 @@ struct ProfileManifest
                 for (auto & p : e["storePaths"])
                     element.storePaths.insert(state.store->parseStorePath((std::string) p));
                 element.active = e["active"];
+                if(e.contains("priority")) {
+                    element.priority = e["priority"];
+                }
                 if (e.value(sUrl, "") != "") {
                     element.source = ProfileElementSource {
                         parseFlakeRef(e[sOriginalUrl]),
@@ -153,6 +156,7 @@ struct ProfileManifest
             nlohmann::json obj;
             obj["storePaths"] = paths;
             obj["active"] = element.active;
+            obj["priority"] = element.priority;
             if (element.source) {
                 obj["originalUrl"] = element.source->originalRef.to_string();
                 obj["url"] = element.source->resolvedRef.to_string();
@@ -177,7 +181,7 @@ struct ProfileManifest
         for (auto & element : elements) {
             for (auto & path : element.storePaths) {
                 if (element.active)
-                    pkgs.emplace_back(store->printStorePath(path), true, 5);
+                    pkgs.emplace_back(store->printStorePath(path), true, element.priority);
                 references.insert(path);
             }
         }
@@ -259,6 +263,16 @@ builtPathsPerInstallable(
 
 struct CmdProfileInstall : InstallablesCommand, MixDefaultProfile
 {
+    std::optional<int> priority;
+    CmdProfileInstall() {
+        addFlag({
+            .longName = "priority",
+            .description = "The priority of the package to install.",
+            .labels = {"priority"},
+            .handler = {&priority},
+        });
+    };
+
     std::string description() override
     {
         return "install a package into a profile";
@@ -282,6 +296,8 @@ struct CmdProfileInstall : InstallablesCommand, MixDefaultProfile
         for (auto & installable : installables) {
             ProfileElement element;
 
+
+
             if (auto installable2 = std::dynamic_pointer_cast<InstallableFlake>(installable)) {
                 // FIXME: make build() return this?
                 auto [attrPath, resolvedRef, drv] = installable2->toDerivation();
@@ -291,8 +307,16 @@ struct CmdProfileInstall : InstallablesCommand, MixDefaultProfile
                     attrPath,
                     installable2->outputsSpec
                 };
+
+                if(drv.priority) {
+                    element.priority = *drv.priority;
+                }
             }
 
+            if(priority) { // if --priority was specified we want to override the priority of the installable
+                element.priority = *priority;
+            };
+
             element.updateStorePaths(getEvalStore(), store, builtPaths[installable.get()]);
 
             manifest.elements.push_back(std::move(element));
diff --git a/tests/nix-profile.sh b/tests/nix-profile.sh
index f8da3d929..7ba3235fa 100644
--- a/tests/nix-profile.sh
+++ b/tests/nix-profile.sh
@@ -120,3 +120,21 @@ nix profile install "$flake1Dir^man"
 (! [ -e $TEST_HOME/.nix-profile/bin/hello ])
 [ -e $TEST_HOME/.nix-profile/share/man ]
 (! [ -e $TEST_HOME/.nix-profile/include ])
+
+# test priority
+nix profile remove 0
+
+# Make another flake.
+flake2Dir=$TEST_ROOT/flake2
+printf World > $flake1Dir/who
+cp -r $flake1Dir $flake2Dir
+printf World2 > $flake2Dir/who
+
+nix profile install $flake1Dir
+[[ $($TEST_HOME/.nix-profile/bin/hello) = "Hello World" ]]
+nix profile install $flake2Dir --priority 100
+[[ $($TEST_HOME/.nix-profile/bin/hello) = "Hello World" ]]
+nix profile install $flake2Dir --priority 0
+[[ $($TEST_HOME/.nix-profile/bin/hello) = "Hello World2" ]]
+# nix profile install $flake1Dir --priority 100
+# [[ $($TEST_HOME/.nix-profile/bin/hello) = "Hello World" ]]