diff --git a/src/libstore/content-address.cc b/src/libstore/content-address.cc
index 5bf51cb97..7de5c0874 100644
--- a/src/libstore/content-address.cc
+++ b/src/libstore/content-address.cc
@@ -31,7 +31,7 @@ template<class... Ts> overloaded(Ts...) -> overloaded<Ts...>;
 std::string renderContentAddress(ContentAddress ca) {
     return std::visit(overloaded {
         [](TextHash th) {
-            return "text:" + th.hash.to_string(Base::Base32, true);
+            return "text:" + th.hash.to_string(Base32, true);
         },
         [](FileSystemHash fsh) {
             return makeFixedOutputCA(fsh.method, fsh.hash);
diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index 1ba957c4a..6383e31f4 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -267,7 +267,7 @@ string Derivation::unparse(const Store & store, bool maskOutputs,
         s += ','; printUnquotedString(s, maskOutputs ? "" : store.printStorePath(i.second.path));
         s += ','; printUnquotedString(s, i.second.hash ? i.second.hash->printMethodAlgo() : "");
         s += ','; printUnquotedString(s,
-            i.second.hash ? i.second.hash->hash.to_string(Base::Base16, false) : "");
+            i.second.hash ? i.second.hash->hash.to_string(Base16, false) : "");
         s += ')';
     }
 
@@ -467,7 +467,7 @@ void writeDerivation(Sink & out, const Store & store, const BasicDerivation & dr
         out << i.first
             << store.printStorePath(i.second.path)
             << i.second.hash->printMethodAlgo()
-            << i.second.hash->hash.to_string(Base::Base16, false);
+            << i.second.hash->hash.to_string(Base16, false);
     writeStorePaths(store, out, drv.inputSrcs);
     out << drv.platform << drv.builder << drv.args;
     out << drv.env.size();
diff --git a/src/libutil/hash.cc b/src/libutil/hash.cc
index 7a8d091df..b187249e9 100644
--- a/src/libutil/hash.cc
+++ b/src/libutil/hash.cc
@@ -223,7 +223,7 @@ Hash newHashAllowEmpty(std::string hashStr, std::optional<HashType> ht)
         if (!ht)
             throw BadHash("empty hash requires explicit hash type");
         Hash h(*ht);
-        warn("found empty hash, assuming '%s'", h.to_string(Base::SRI, true));
+        warn("found empty hash, assuming '%s'", h.to_string(SRI, true));
         return h;
     } else
         return Hash(hashStr, ht);
diff --git a/src/nix/show-derivation.cc b/src/nix/show-derivation.cc
index 9132c75b1..5d77cfdca 100644
--- a/src/nix/show-derivation.cc
+++ b/src/nix/show-derivation.cc
@@ -72,7 +72,7 @@ struct CmdShowDerivation : InstallablesCommand
                     outputObj.attr("path", store->printStorePath(output.second.path));
                     if (output.second.hash) {
                         outputObj.attr("hashAlgo", output.second.hash->printMethodAlgo());
-                        outputObj.attr("hash", output.second.hash->hash.to_string(Base::Base16, false));
+                        outputObj.attr("hash", output.second.hash->hash.to_string(Base16, false));
                     }
                 }
             }