diff --git a/src/log.c b/src/log.c
index 69116c7b..05a235fa 100644
--- a/src/log.c
+++ b/src/log.c
@@ -39,7 +39,7 @@ char *errorfilename;
 char *shmlogname = "";
 /* Size limit for the SHM log, by default 25 MiB. Can be overwritten using the
  * flag --shmlog-size. */
-int shmlog_size = 25 * 1024 * 1024;
+int shmlog_size = 0;
 /* If enabled, logbuffer will point to a memory mapping of the i3 SHM log. */
 static char *logbuffer;
 /* A pointer (within logbuffer) where data will be written to next. */
diff --git a/src/main.c b/src/main.c
index aefdfb27..45cb162c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -284,8 +284,7 @@ int main(int argc, char *argv[]) {
     debug_build = ((strchr(I3_VERSION, '(') - I3_VERSION) > 10);
 
     /* On non-release builds, disable SHM logging by default. */
-    if (!debug_build)
-        shmlog_size = 0;
+    shmlog_size = (debug_build ? 25 * 1024 * 1024 : 0);
 
     start_argv = argv;