diff --git a/src/backend.c b/src/backend.c
index bff2917..6f20fc3 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -12,9 +12,11 @@ f2b_backend_create(f2b_config_section_t *config, const char *id) {
   assert(config != NULL);
   assert(config->type == t_backend);
 
-  f2b_config_find_param(config->param, BACKEND_LIBRARY_PARAM);
-  if (!param)
+  param = f2b_config_find_param(config->param, BACKEND_LIBRARY_PARAM);
+  if (!param) {
+    f2b_log_msg(log_error, "can't find '%s' param in backend config", BACKEND_LIBRARY_PARAM);
     return NULL;
+  }
 
   if ((backend = calloc(1, sizeof(f2b_backend_t))) == NULL)
     return NULL;
@@ -64,6 +66,7 @@ f2b_backend_create(f2b_config_section_t *config, const char *id) {
   f2b_log_msg(log_error, "backend '%s' not fully configured", config->name);
 
   cleanup:
+  f2b_log_msg(log_error, "load error: %s", dlerror());
   if (backend->h) {
     if (backend->cfg && backend->destroy)
       backend->destroy(backend->cfg);
diff --git a/src/common.h b/src/common.h
index b5a01be..0eefac2 100644
--- a/src/common.h
+++ b/src/common.h
@@ -7,8 +7,9 @@
 #include <dlfcn.h>
 #include <errno.h>
 #include <limits.h>
-#include <stdio.h>
+#include <stdarg.h>
 #include <stdbool.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
diff --git a/src/config.c b/src/config.c
index a2fe832..0dc254f 100644
--- a/src/config.c
+++ b/src/config.c
@@ -40,7 +40,7 @@ f2b_config_parse_kv_pair(const char *src) {
   p = value + strlen(value);
   if (p > value)
     p--; /* step back at char before '\0' */
-  while (p > value && isblank(*p))
+  while (p > value && isspace(*p))
     p--;
   p++, *p = '\0';
 
@@ -147,7 +147,7 @@ f2b_config_load(const char *path) {
   size_t linenum = 0; /* current line number in config */
 
   if ((f = fopen(path, "r")) == NULL) {
-    f2b_log_msg(log_error, "can't open config file: %s: %s", path, strerror(errno));
+    f2b_log_msg(log_error, "can't open config file '%s': %s", path, strerror(errno));
     return NULL;
   }
 
diff --git a/src/log.c b/src/log.c
index 1d443d7..5482ad7 100644
--- a/src/log.c
+++ b/src/log.c
@@ -1,7 +1,3 @@
-#include <stdarg.h>
-#include <stdio.h>
-#include <string.h>
-
 #include "common.h"
 #include "log.h"
 
@@ -26,9 +22,12 @@ void f2b_log_msg(log_msgtype_t l, const char *fmt, ...) {
     return;
 
   va_start(args, fmt);
-  snprintf(msg, sizeof(msg), fmt, args);
+  vsnprintf(msg, sizeof(msg), fmt, args);
   va_end(args);
-  printf(line, LOGLINE_MAX, "[%s] %s", loglevels[l], msg);
+  snprintf(line, LOGLINE_MAX, "[%s] %s", loglevels[l], msg);
+  /* TODO */
+  fputs(line, stderr);
+  fputc('\n', stderr);
 
   return;
 }