diff --git a/source/build/src/sdlayer.cpp b/source/build/src/sdlayer.cpp
index 92be78451..fc147d928 100644
--- a/source/build/src/sdlayer.cpp
+++ b/source/build/src/sdlayer.cpp
@@ -726,10 +726,11 @@ void initputs(const char *buf)
     OSD_Puts(buf);
 //    Bprintf("%s", buf);
 
-    mutex_lock(&m_initprintf);
     if (Bstrlen(dabuf) + Bstrlen(buf) > 1022)
     {
+        mutex_lock(&m_initprintf);
         startwin_puts(dabuf);
+        mutex_unlock(&m_initprintf);
         Bmemset(dabuf, 0, sizeof(dabuf));
     }
 
@@ -737,7 +738,9 @@ void initputs(const char *buf)
 
     if (g_logFlushWindow || Bstrlen(dabuf) > 768)
     {
+        mutex_lock(&m_initprintf);
         startwin_puts(dabuf);
+        mutex_unlock(&m_initprintf);
 #ifndef _WIN32
         startwin_idle(NULL);
 #else
@@ -745,7 +748,6 @@ void initputs(const char *buf)
 #endif
         Bmemset(dabuf, 0, sizeof(dabuf));
     }
-    mutex_unlock(&m_initprintf);
 }
 
 //