diff --git a/source/compiler/sc2.c b/source/compiler/sc2.c
index 821f2a80..3398c59a 100644
--- a/source/compiler/sc2.c
+++ b/source/compiler/sc2.c
@@ -1538,8 +1538,6 @@ static int command(void)
 #endif
   case tpERROR:
   case tpWARNING:
-    while (*lptr<=' ' && *lptr!='\0')
-      lptr++;
     while (*lptr<=' ' && *lptr!='\0')
       lptr++;
     if (!SKIPPING) {
@@ -1547,7 +1545,7 @@ static int command(void)
       if (usermsg!=NULL) {
         char *ptr=usermsg+strlen(usermsg)-1;
         /* remove trailing whitespace and newlines */
-        while (*ptr<=' ')
+        while (ptr >= usermsg && *ptr<=' ')
           *ptr--='\0';
         if (tok==tpERROR)
           error(111,usermsg); /* user error */
diff --git a/source/compiler/tests/empty_warning_crash_gh_339.meta b/source/compiler/tests/empty_warning_crash_gh_339.meta
new file mode 100644
index 00000000..4a36e685
--- /dev/null
+++ b/source/compiler/tests/empty_warning_crash_gh_339.meta
@@ -0,0 +1,6 @@
+{
+  'test_type': 'output_check',
+  'errors': """
+empty_warning_crash_gh_339.pwn(1) : warning 237: user warning:
+"""
+}
diff --git a/source/compiler/tests/empty_warning_crash_gh_339.pwn b/source/compiler/tests/empty_warning_crash_gh_339.pwn
new file mode 100644
index 00000000..fe5b88e2
--- /dev/null
+++ b/source/compiler/tests/empty_warning_crash_gh_339.pwn
@@ -0,0 +1,3 @@
+#warning
+
+main () {}
\ No newline at end of file