diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -203,8 +203,10 @@
 
 if(ENABLE_WERROR)
 	add_compiler_flags(
-		-Werror=vla
+		-Werror=return-type
+		-Werror=switch
 		-Werror=thread-safety-analysis
+		-Werror=vla
 	)
 endif()
 
diff --git a/src/psbt.cpp b/src/psbt.cpp
--- a/src/psbt.cpp
+++ b/src/psbt.cpp
@@ -278,7 +278,7 @@
     return TransactionError::OK;
 }
 
-std::string PSBTRoleName(PSBTRole role) {
+std::string PSBTRoleName(const PSBTRole role) {
     switch (role) {
         case PSBTRole::UPDATER:
             return "updater";
@@ -289,6 +289,7 @@
         case PSBTRole::EXTRACTOR:
             return "extractor";
     }
+    assert(false);
 }
 
 bool DecodeBase64PSBT(PartiallySignedTransaction &psbt,