diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index e56be625..10cde870 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -55,7 +55,7 @@ void BinaryCacheStore::init()
 }
 
 void BinaryCacheStore::getFile(const std::string & path,
-    Callback<std::shared_ptr<std::string>> callback)
+    Callback<std::shared_ptr<std::string>> callback) noexcept
 {
     try {
         callback(getFile(path));
@@ -240,7 +240,7 @@ void BinaryCacheStore::narFromPath(const Path & storePath, Sink & sink)
 }
 
 void BinaryCacheStore::queryPathInfoUncached(const Path & storePath,
-    Callback<std::shared_ptr<ValidPathInfo>> callback)
+    Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept
 {
     auto uri = getUri();
     auto act = std::make_shared<Activity>(*logger, lvlTalkative, actQueryPathInfo,
diff --git a/src/libstore/binary-cache-store.hh b/src/libstore/binary-cache-store.hh
index 953f3b90..af108880 100644
--- a/src/libstore/binary-cache-store.hh
+++ b/src/libstore/binary-cache-store.hh
@@ -47,7 +47,7 @@ public:
     /* Fetch the specified file and call the specified callback with
        the result. A subclass may implement this asynchronously. */
     virtual void getFile(const std::string & path,
-        Callback<std::shared_ptr<std::string>> callback);
+        Callback<std::shared_ptr<std::string>> callback) noexcept;
 
     std::shared_ptr<std::string> getFile(const std::string & path);
 
@@ -73,7 +73,7 @@ public:
     bool isValidPathUncached(const Path & path) override;
 
     void queryPathInfoUncached(const Path & path,
-        Callback<std::shared_ptr<ValidPathInfo>> callback) override;
+        Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept override;
 
     Path queryPathFromHashPart(const string & hashPart) override
     { unsupported("queryPathFromHashPart"); }
diff --git a/src/libstore/http-binary-cache-store.cc b/src/libstore/http-binary-cache-store.cc
index e631d95f..779f89e6 100644
--- a/src/libstore/http-binary-cache-store.cc
+++ b/src/libstore/http-binary-cache-store.cc
@@ -131,7 +131,7 @@ protected:
     }
 
     void getFile(const std::string & path,
-        Callback<std::shared_ptr<std::string>> callback) override
+        Callback<std::shared_ptr<std::string>> callback) noexcept override
     {
         checkEnabled();
 
diff --git a/src/libstore/legacy-ssh-store.cc b/src/libstore/legacy-ssh-store.cc
index 7c9bc2b6..d5fbdd25 100644
--- a/src/libstore/legacy-ssh-store.cc
+++ b/src/libstore/legacy-ssh-store.cc
@@ -88,7 +88,7 @@ struct LegacySSHStore : public Store
     }
 
     void queryPathInfoUncached(const Path & path,
-        Callback<std::shared_ptr<ValidPathInfo>> callback) override
+        Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept override
     {
         try {
             auto conn(connections->get());
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 63b11467..2fcf0849 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -629,7 +629,7 @@ uint64_t LocalStore::addValidPath(State & state,
 
 
 void LocalStore::queryPathInfoUncached(const Path & path,
-    Callback<std::shared_ptr<ValidPathInfo>> callback)
+    Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept
 {
     try {
         auto info = std::make_shared<ValidPathInfo>();
diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index af8b84bf..3ae34c40 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -127,7 +127,7 @@ public:
     PathSet queryAllValidPaths() override;
 
     void queryPathInfoUncached(const Path & path,
-        Callback<std::shared_ptr<ValidPathInfo>> callback) override;
+        Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept override;
 
     void queryReferrers(const Path & path, PathSet & referrers) override;
 
diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index 1c2e23f9..e38fe49a 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -349,7 +349,7 @@ void RemoteStore::querySubstitutablePathInfos(const PathSet & paths,
 
 
 void RemoteStore::queryPathInfoUncached(const Path & path,
-    Callback<std::shared_ptr<ValidPathInfo>> callback)
+    Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept
 {
     try {
         std::shared_ptr<ValidPathInfo> info;
diff --git a/src/libstore/remote-store.hh b/src/libstore/remote-store.hh
index 80f18ab7..82fbec09 100644
--- a/src/libstore/remote-store.hh
+++ b/src/libstore/remote-store.hh
@@ -41,7 +41,7 @@ public:
     PathSet queryAllValidPaths() override;
 
     void queryPathInfoUncached(const Path & path,
-        Callback<std::shared_ptr<ValidPathInfo>> callback) override;
+        Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept override;
 
     void queryReferrers(const Path & path, PathSet & referrers) override;
 
diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index 88a5b2f4..5f63c53b 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -329,13 +329,14 @@ ref<const ValidPathInfo> Store::queryPathInfo(const Path & storePath)
 
 
 void Store::queryPathInfo(const Path & storePath,
-    Callback<ref<ValidPathInfo>> callback)
+    Callback<ref<ValidPathInfo>> callback) noexcept
 {
-    assertStorePath(storePath);
-
-    auto hashPart = storePathToHash(storePath);
+    std::string hashPart;
 
     try {
+        assertStorePath(storePath);
+
+        hashPart = storePathToHash(storePath);
 
         {
             auto res = state.lock()->pathInfoCache.get(hashPart);
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index 59967737..7fb56860 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -360,12 +360,12 @@ public:
 
     /* Asynchronous version of queryPathInfo(). */
     void queryPathInfo(const Path & path,
-        Callback<ref<ValidPathInfo>> callback);
+        Callback<ref<ValidPathInfo>> callback) noexcept;
 
 protected:
 
     virtual void queryPathInfoUncached(const Path & path,
-        Callback<std::shared_ptr<ValidPathInfo>> callback) = 0;
+        Callback<std::shared_ptr<ValidPathInfo>> callback) noexcept = 0;
 
 public:
 
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 686e81d3..07c3d28f 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -460,7 +460,7 @@ public:
         if (prev) done.test_and_set();
     }
 
-    void operator()(T && t)
+    void operator()(T && t) noexcept
     {
         auto prev = done.test_and_set();
         assert(!prev);
@@ -469,7 +469,7 @@ public:
         fun(promise.get_future());
     }
 
-    void rethrow(const std::exception_ptr & exc = std::current_exception())
+    void rethrow(const std::exception_ptr & exc = std::current_exception()) noexcept
     {
         auto prev = done.test_and_set();
         assert(!prev);