diff --git a/src/backends/backend.c b/src/backends/backend.c
index 1decda2..f5aeb54 100644
--- a/src/backends/backend.c
+++ b/src/backends/backend.c
@@ -69,7 +69,7 @@ log_msg(const cfg_t *cfg, enum loglevel lvl, const char *format, ...) {
   va_list args;
   size_t len;
 
-  len = snprintf(buf, sizeof(buf), "backend/%s ", MODNAME);
+  len = snprintf(buf, sizeof(buf), "backend/%s: ", MODNAME);
   va_start(args, format);
   vsnprintf(buf + len, sizeof(buf) - len, format, args);
   va_end(args);
diff --git a/src/filters/filter.c b/src/filters/filter.c
index de46d33..2f491cd 100644
--- a/src/filters/filter.c
+++ b/src/filters/filter.c
@@ -19,7 +19,7 @@ log_msg(const cfg_t *cfg, enum loglevel lvl, const char *format, ...) {
   va_list args;
   size_t len;
 
-  len = snprintf(buf, sizeof(buf), "filter/%s ", MODNAME);
+  len = snprintf(buf, sizeof(buf), "filter/%s: ", MODNAME);
   va_start(args, format);
   vsnprintf(buf + len, sizeof(buf) - len, format, args);
   va_end(args);
diff --git a/src/sources/source.c b/src/sources/source.c
index ce8a370..dfe260f 100644
--- a/src/sources/source.c
+++ b/src/sources/source.c
@@ -21,7 +21,7 @@ log_msg(const cfg_t *cfg, enum loglevel lvl, const char *format, ...) {
   va_list args;
   size_t len;
 
-  len = snprintf(buf, sizeof(buf), "source/%s ", MODNAME);
+  len = snprintf(buf, sizeof(buf), "source/%s: ", MODNAME);
   va_start(args, format);
   vsnprintf(buf + len, sizeof(buf) - len, format, args);
   va_end(args);