diff --git a/configure.ac b/configure.ac
index bc2f1c50..ee8f8562 100644
--- a/configure.ac
+++ b/configure.ac
@@ -90,6 +90,8 @@ dnl ######################################################################
 
 AC_PROG_GREP
 AC_PROG_EGREP
+: ${CFLAGS=""}
+: ${CPPFLAGS=""}
 AC_PROG_CC
 AC_PROG_MKDIR_P
 AC_EXEEXT
@@ -1283,8 +1285,8 @@ dnl ######################################################################
 dnl Collect all the options
 dnl ######################################################################
 
-CORE_CPPFLAGS="$PCRE2_CPPFLAGS $OPENSSL_CPPFLAGS $LIBYAML_CPPFLAGS $CPPFLAGS"
-CORE_CFLAGS="$PCRE2_CFLAGS $OPENSSL_CFLAGS $LIBYAML_CFLAGS $CFLAGS"
+CORE_CPPFLAGS="$PCRE2_CPPFLAGS $OPENSSL_CPPFLAGS $LIBYAML_CPPFLAGS"
+CORE_CFLAGS="$PCRE2_CFLAGS $OPENSSL_CFLAGS $LIBYAML_CFLAGS"
 CORE_LDFLAGS="$PCRE2_LDFLAGS $OPENSSL_LDFLAGS $LIBYAML_LDFLAGS $LDFLAGS"
 CORE_LIBS="$PCRE2_LIBS $OPENSSL_LIBS $LIBYAML_LIBS $LIBS"
 
diff --git a/libutils/buffer.c b/libutils/buffer.c
index 861bf1cd..44a4e993 100644
--- a/libutils/buffer.c
+++ b/libutils/buffer.c
@@ -721,7 +721,7 @@ const char* BufferSearchAndReplace(Buffer *buffer, const char *pattern,
         ret = pcre2_substitute(regex, (PCRE2_SPTR) BufferData(buffer), BufferSize(buffer),
                                0, subst_opts, match_data, NULL,
                                (PCRE2_SPTR) substitute, PCRE2_ZERO_TERMINATED,
-                               result, &out_size);
+                               (PCRE2_UCHAR8 *) result, &out_size);
         if (ret == PCRE2_ERROR_NOMEMORY)
         {
             result = xrealloc(result, out_size);
diff --git a/libutils/json-yaml.c b/libutils/json-yaml.c
index 24dcd01e..7fc85914 100644
--- a/libutils/json-yaml.c
+++ b/libutils/json-yaml.c
@@ -161,7 +161,7 @@ static void JsonParseYamlData(yaml_parser_t *parser, JsonElement *element, const
                     if (key == NULL)
                     {
                         // save key
-                        key = xstrdup(event.data.scalar.value);
+                        key = xstrdup((const char *)event.data.scalar.value);
                     }
                     else
                     {
@@ -343,7 +343,7 @@ JsonParseError JsonParseYamlString(const char **data, JsonElement **json_out)
         return JSON_PARSE_ERROR_LIBYAML_FAILURE;
     }
 
-    yaml_parser_set_input_string(&parser, *data, strlen(*data));
+    yaml_parser_set_input_string(&parser, (const unsigned char *) *data, strlen(*data));
 
     JsonElement *holder = JsonArrayCreate(1);
     JsonParseYamlData(&parser, holder, 0);