diff --git a/src/lib/icu/Collate.cxx b/src/lib/icu/Collate.cxx
index aa5df4e47..b6fc9e136 100644
--- a/src/lib/icu/Collate.cxx
+++ b/src/lib/icu/Collate.cxx
@@ -99,13 +99,16 @@ IcuCollate(const char *a, const char *b)
 #else
 	/* fall back to ucol_strcoll() */
 
-	const auto au = UCharFromUTF8(a);
-	const auto bu = UCharFromUTF8(b);
+	try {
+		const auto au = UCharFromUTF8(a);
+		const auto bu = UCharFromUTF8(b);
 
-	return !au.IsNull() && !bu.IsNull()
-		? (int)ucol_strcoll(collator, au.begin(), au.size(),
-				    bu.begin(), bu.size())
-		: strcasecmp(a, b);
+		return ucol_strcoll(collator, au.begin(), au.size(),
+				    bu.begin(), bu.size());
+	} catch (const std::runtime_error &) {
+		/* fall back to plain strcasecmp() */
+		return strcasecmp(a, b);
+	}
 #endif
 
 #elif defined(WIN32)
diff --git a/src/lib/icu/Converter.cxx b/src/lib/icu/Converter.cxx
index 7d1a45382..815697821 100644
--- a/src/lib/icu/Converter.cxx
+++ b/src/lib/icu/Converter.cxx
@@ -129,7 +129,7 @@ try {
 
 AllocatedString<char>
 IcuConverter::FromUTF8(const char *s) const
-{
+try {
 #ifdef HAVE_ICU
 	const ScopeLock protect(mutex);
 
@@ -156,6 +156,8 @@ IcuConverter::FromUTF8(const char *s) const
 #elif defined(HAVE_ICONV)
 	return DoConvert(from_utf8, s);
 #endif
+} catch (const std::runtime_error &) {
+	return nullptr;
 }
 
 #endif
diff --git a/src/lib/icu/Util.cxx b/src/lib/icu/Util.cxx
index 9a8c44b9c..9342001f2 100644
--- a/src/lib/icu/Util.cxx
+++ b/src/lib/icu/Util.cxx
@@ -47,7 +47,7 @@ UCharFromUTF8(const char *src)
 		      src, src_length,
 		      &error_code);
 	if (U_FAILURE(error_code))
-		return {};
+		throw std::runtime_error(u_errorName(error_code));
 
 	dest.SetSize(dest_length);
 	return dest;
diff --git a/src/lib/icu/Util.hxx b/src/lib/icu/Util.hxx
index bae694bc6..863f32c22 100644
--- a/src/lib/icu/Util.hxx
+++ b/src/lib/icu/Util.hxx
@@ -30,6 +30,8 @@ template<typename T> class AllocatedString;
 
 /**
  * Wrapper for u_strFromUTF8().
+ *
+ * Throws std::runtime_error on error.
  */
 AllocatedArray<UChar>
 UCharFromUTF8(const char *src);