diff --git a/setup/build.py b/setup/build.py
index c443a6b9c9..0561d52a5a 100644
--- a/setup/build.py
+++ b/setup/build.py
@@ -48,6 +48,7 @@ class Extension(object):
         self.error = d['error'] = kwargs.get('error', None)
         self.libraries = d['libraries'] = kwargs.get('libraries', [])
         self.cflags = d['cflags'] = kwargs.get('cflags', [])
+        self.uses_icu = 'icuuc' in self.libraries
         if iswindows:
             self.cflags.append('/DCALIBRE_MODINIT_FUNC=PyMODINIT_FUNC')
             if self.needs_cxx and kwargs.get('needs_c++14'):
@@ -399,7 +400,7 @@ class Build(Command):
         cmd = [linker]
         if iswindows:
             pre_ld_flags = []
-            if ext.name in ('icu', 'matcher'):
+            if ext.uses_icu:
                 # windows has its own ICU libs that dont work
                 pre_ld_flags = elib
             cmd += pre_ld_flags + self.env.ldflags + ext.ldflags + elib + xlib + \
diff --git a/src/calibre/db/sqlite_extension.cpp b/src/calibre/db/sqlite_extension.cpp
index 3c53d22ece..01f5eb3bb5 100644
--- a/src/calibre/db/sqlite_extension.cpp
+++ b/src/calibre/db/sqlite_extension.cpp
@@ -197,7 +197,7 @@ tok_create(void *sqlite3, const char **azArg, int nArg, Fts5Tokenizer **ppOut) {
             rc = p->constructor_error;
             delete p;
         }
-    } catch (std::bad_alloc &ex) {
+    } catch (std::bad_alloc) {
         return SQLITE_NOMEM;
     } catch (...) {
         return SQLITE_ERROR;
@@ -210,7 +210,7 @@ tok_tokenize(Fts5Tokenizer *tokenizer_ptr, void *callback_ctx, int flags, const
     Tokenizer *p = reinterpret_cast<Tokenizer*>(tokenizer_ptr);
     try {
         return p->tokenize(callback_ctx, flags, text, text_sz, callback);
-    } catch (std::bad_alloc &ex) {
+    } catch (std::bad_alloc) {
         return SQLITE_NOMEM;
     } catch (...) {
         return SQLITE_ERROR;