diff --git a/src/tests/Makefile.am b/src/tests/Makefile.am
index d1c6372e..1bd7be3f 100644
--- a/src/tests/Makefile.am
+++ b/src/tests/Makefile.am
@@ -24,6 +24,12 @@ INCLUDES=$(XAPIAN_CXXFLAGS)					\
 	-DMU_PROGRAM=\"${abs_top_builddir}/src/mu\"		\
 	-DABS_SRCDIR=\"${abs_srcdir}\"
 
+# don't use -Werror, as it might break on other compilers
+# use -Wno-unused-parameters, because some callbacks may not
+# really need all the params they get
+AM_CFLAGS=-Wall -Wextra -Wno-unused-parameter -Wdeclaration-after-statement
+AM_CXXFLAGS=-Wall -Wextra -Wno-unused-parameter
+
 noinst_PROGRAMS= $(TEST_PROGS)
 
 noinst_LTLIBRARIES=libtestmucommon.la
diff --git a/src/tests/test-mu-msg.c b/src/tests/test-mu-msg.c
index b3cff1b6..88c57e3c 100644
--- a/src/tests/test-mu-msg.c
+++ b/src/tests/test-mu-msg.c
@@ -156,7 +156,6 @@ static void
 test_mu_msg_03 (void)
 {
 	MuMsg *msg;
-	int i;
 
 	msg = mu_msg_new (MU_TESTMAILDIR
 			  "cur/1283599333.1840_11.cthulhu!2,", NULL);
@@ -179,12 +178,12 @@ test_mu_msg_03 (void)
 }
 
 
-static gboolean
-ignore_error (const char* log_domain, GLogLevelFlags log_level, const gchar* msg,
-	      gpointer user_data)
-{
-	return FALSE; /* don't abort */
-}
+/* static gboolean */
+/* ignore_error (const char* log_domain, GLogLevelFlags log_level, const gchar* msg, */
+/* 	      gpointer user_data) */
+/* { */
+/* 	return FALSE; /\* don't abort *\/ */
+/* } */
 
 static void
 shutup (void) {}
diff --git a/src/tests/test-mu-query.c b/src/tests/test-mu-query.c
index 33ce9dd5..d570c3eb 100644
--- a/src/tests/test-mu-query.c
+++ b/src/tests/test-mu-query.c
@@ -62,17 +62,17 @@ run_and_count_matches (const char *xpath, const char *query)
 	MuQuery  *mquery;
 	MuMsgIter *iter;
 	guint count;
-	gchar *prep;
 	
 	mquery = mu_query_new (xpath);
 	g_assert (query);
 
 	iter = mu_query_run (mquery, query, NULL, FALSE, 1);
 	g_assert (iter);
-
-	/* prep = mu_query_preprocess (query); */
-	/* g_print ("\n%s:\n(1)'%s'\n(2)'%s'\n", xpath, query, prep); */
-	/* g_free (prep); */
+	{
+		gchar *prep = mu_query_preprocess (query);
+		g_print ("\n%s:\n(1)'%s'\n(2)'%s'\n", xpath, query, prep);
+		g_free (prep);
+	}
 	
 	for (count = 0; !mu_msg_iter_is_done(iter);
 	     mu_msg_iter_next(iter), ++count);
@@ -92,7 +92,6 @@ typedef struct  {
 static void
 test_mu_query_01 (void)
 {
-	MuQuery *query;
 	gchar *xpath;
 	int i;
 	
@@ -136,7 +135,6 @@ test_mu_query_02 (void)
 static void
 test_mu_query_03 (void)
 {
-	MuQuery *query;
 	gchar *xpath;
 	int i;
 	
@@ -162,7 +160,6 @@ test_mu_query_03 (void)
 static void
 test_mu_query_04 (void)
 {
-	MuQuery *query;
 	gchar *xpath;
 	int i;